Last Year, I attended Apple's WWDC for the first time.  Below are some suggestions for new arrivals based on my first trip there.

Pilgrimage to the Mothership

Every year someone plans the annual pilgrimage to the mothership, i.e. a visit to the Apple Corporate Headquarters.  Last year I atteded this.  Everyone met outside the Moscone center and boarded a couple of chartered buses for the trip down to Cupertino.  Once we arrived there, we spent an hour or so visiting the on-site Apple Store.  You can find some nice, exclusive gifts and t-shirts here.  After that, we went over to a restaurant in the parking lot of the Apple HQ and had lunch.

All in all, I found this trip kind of a let down.  The only thing you are allowed to see at the Apple HQ is the Apple Store.  If you want to buy a few t-shirts I suppose that's a good thing, but otherwise, it's not much different from visiting any other Apple Store.  It's also a fairly small Apple Store at that.  The food was decent at the restaurant.  If you are a first time attendee of WWDC, you might enjoy this trip, but once you've gone once, it kind of loses it's appeal.

Flights

If possible, book a nonstop flight!  Yes, it costs a bit more, but it's worth it.  I went cheap last year and booked flights both ways with stopovers.  I live in South Florida - about as far from California as you can possibly be and still be in the same country!  These stopovers added several hours of travel time and were a real hassle.  This year, I'm travelling nonstop so instead of 10+ hours of travel, it's down to 6 hours.  Also, if your airline offers seats in coach with extra legroom and you are a tall person, get it!  Coach seats are very cramped, especially legroom.  The seatback tables in coach are also tiny..  If you have a big laptop, forget it.  It will never fit.  A Macbook Air or an iPad would certainly fit though.

Suitcases

Pay close attention to the maximum weight your airline allows for checked baggage.  If you go over that, they charge really high fees.  Weigh your suitcase before you leave.  If it's over the weight limit, leave some things behind.  For example, you can leave such things as many toiletries (toothpaste, deoderant, shampoo etc.) behind.  There is a Walgreens around the corner from Moscone if you need these things and it's a lot cheaper to buy them there and toss them than to pay the suitcase overweight charges.  Also, leave some space and weight free in your suitcase for bringing items back.  You are going to be coming back with at least a new WWDC jacket and likely a few t-shirts so keep the weight of thse things in mind.  Also, if you must go over the limit, you can move some items into a carry-on bag and take that on the plane with you.  Most airlines allow one carry on bag, but a laptop bag does NOT count as a carry on bag, so you can carry on a laptop bag and a carry on bag, for these extra items.

Hotels

Hotels in San Francisco are very expensive.  A cheap hotel is at least $200/night.  A good hotel can be several times that.  If you want to stay in a decent, relatively cheap hotel, The Pickwick Hotel is a good choice.  I stayed there last year and it was a clean and well kept hotel, if nothing fancy.  The Pickwick Hotel is about a block or so from the Moscone Center so it's very close.  This year, I have a bit more money to spare on the trip so I'm staying at the Intercontinental Hotel.  This hotel runs about $350 or more a night.  It's a large 30+ story hotel directly behind the Moscone Center.  This is about as close as you can get to staying in the Moscone Center itself!

The Keynote

The keynote is the first event Monday morning.  Get there EARLY.  It usually starts at 10AM.  I got there at about 7AM and the line was already 3/4 of the way around the Moscone Center!  You might want to get there even earlier than that to insure a good seat.  The room where the keynote is very large and will hold most of the people who are attending, so even if you get there relatively late, you should still be able to get a seat.  If not, they have an overflow room where you can watch it on video.

Sanitation

Most of the attendees at WWDC are men.  Probably 90-95%.  This means that the bathrooms are going to be VERY heavily used and get kind of gross by the end of the day.  If you are a female attendee, you are lucky.  You'll have the bathrooms all to yourself.  If you want to find a clean bathroom, try to locate some of the more out of the way locations.  The bathrooms in the front, and the ones near the large conference rooms will get the most use, so avoid those if you can.  There are several bathrooms located in a corner in the back of each floor.  These are usually fairly clean, so use these instead.  Bring a bottle of hand sanitizer and use if A LOT.  If you don't you will definately get sick by the end of the week.  I did.

Food

Apple provides breakfast and lunch every day, Monday through Friday at the lunch area on the first floor.  This food isn't great, but it's edible.  Breakfast is usually lots of bread - bagels, muffins, etc.  Lunch is usually a pre-made box lunch.  They offer several different lunch choices every day including a vegetarian choice.  They offer sodas, juices and water to drink.  The juices are Odwalla juices.  These are VERY good, but have lots of sugar and calories, so don't go too crazy with those.  They don't provide dinner, so you are on your own there.  You might want to also consider getting to the lunch room a bit early for lunch.  It fills up fast and it can be hard to find a seat.

The downstairs conference room isn't just a place to feed yourself, but a place to feed your laptop / iPhone / iPad as well.  Along the center of every table is a bunch of power strips and ethernet cables.  When you sit down for lunch, you can plug in your laptop to charge it and plug the ethernet cable into your laptop to download all the lastest betas that they offer at the show.  This connection is INCREDIBLY fast, so use this to download software rather than the wifi which is VERY spotty.  If you have a slim laptop such as a Macbook Air or Retina Macbook Pro, don't forget to bring the ethernet adaptor plug for your laptop!

The Sessions

The whole point of going to WWDC is the training sessions they hold throughout the day.  If you see a session that looks interesting, by all means, attend it.  However, if no sessions interest you during a particular hour, don't be afraid to just find a chair / beanbag and relax.  You'll get videos from every session anyway, so yo aren't going to miss anything.  Last year Apple released all the session videos on the Monday following the conference.  This year, they say they'll release them the same day!  I wouldn't be surprised if you can download the videos from the ethernet connections in the first floor lunch room.  Take advantage of this!  And if you do decide to skip a session, sit down next to some other attendees and strike up a conversation with them.  There's no better place for networking with other Apple fans than WWDC.  Chat with them.  Exchange business cards.  Ask what they do.  Be social.

Lunchtime Sessions

Every year, Apple announces some surprise lunchtime sessions.  These are sessions, usually held in the large Presidio conference room on the third floor (the same room where the keynote is held).  These are NOT included in the videos Apple provides after the show is over, so be sure to attend.  These are interesting because they are NOT programming related.  Last year we had Le Var Burton talking about his Reading Rainbow App, and JJ Abrams talking about movie making.  Both were very interesting.  These lunchtime sessions are not to be missed.  One thing to know about these lunch time sessions though is that they are very popular.  There is going to be a LONG line to get into them.  Because there's only about a 15 minute delay between sessions, you are unlikely to be able to attend the lunchtime sessions and the session immediately before it.  Feel free to sneak out of the session before lunch early or skip  it entirely in favor of standing in line for the lunchtime session.

Socializing / Networking

Don't forget to socialize at WWDC.  There is no better place to network.  The videos will cover any sessions you miss, so don't worry about that.  Make time to just sit and relax and chat up the guy/girl next to you.  You may make a friend or even arrange some paying work that way.  There are also often social events outside the Moscone Center in the evenings.  Attend these if you can.  Get out and have some fun!

Acclimitizing to different time zones

If you are flying in from a differnet timezone, you might want to consider flying in a few days early to give yourself some time to adjust to the differernt time zone in California.  I came from Florida, which is only 3 hours off, and I was tired for most of the week until I adjusted.

See the sights

If you've never been to San Francisco, take some time to see the sights.  Check out Alcatraz.  Take a walk across the Golden Gate Bridge.  Go for a ride in a cable car.  You are there already.  You might as well get a little 'tourist-y' while you are there.

Weather

San Francisco is windy and can get quite cold at times.  Wear jeans on your flight over and have a light jacket in your suitcase for when you arrive.  The wind isn't as bad inside the city becasue the tall buildings block a lot of it, but if you are on the bay or walking across the Golden Gate Bridge, it will get cold.

Coming and Going

The conference starts on Monday.  They open Moscone center on the Saturday before to give you a time to register and pick up your ID badge.  Do NOT lose that badge or they won't let you in.  In addition, the last session on Friday ends at noon.  This means that most people will fly in Saturday.  They check in on Saturday.  The show runs Monday through Friday.  Since the show ends at noon on Friday, what most people will do is check out of their hotel Friday morning before they arrive as Moscone.  Then once you get past the last lunch time session, grab your suitcase and head to the airport.  Apple provides a place at Moscone to store your suitcase, but last year, this didn't strike me as a very secure location.  It was just big fenced off area with tons of suitcases piled up.  Personally, I plan on checking out of my hotel Friday morning and then leaving my suitcase at the counter downstairs where they can lock it up in a more secure room.

If you are staying at one of the hotels near Moscone and arriving at San Francisco International Airport, the easiest way to get to your hotel is to take the BART subway from the airport to the Powell Street station.  This station is only a couple blocks from Moscone, so your hotel should be short walk from here.  And of course when you leave, just get back on the subway at this station and take it back to the airport.  As I recall, it costs about $8 each way.  A lot cheaper and faster than a taxi.