I hope this helps everybody. It's something I started working on last year and I'll save it as a Word document and edit it accordingly every year if you guys like it. Feel free to ask questions, add details, etc.
CELEB TABLE
The celeb table and photo booths are divided up by hour (actually 50-55 minutes because of the time needed for the change over). Starting today on the BC/EFA website, they will release the schedule of who is scheduled to appear when. Usually 10-15 celebs appear simultaneously at the celeb table. You pay a certain amount PER HOUR to go down the table and get as many autographs as you want, limited two items per celeb. You can bring your own items, buy the flea market poster and have it signed or they usually have slips of paper set up next to them if you don't have any items with you. At the same time, certain celebs will be removed briefly from the signing table if they've been requested for photos. (See section on photos below.) If you're in line for the signing table but somebody you want a pic with just got called to the photo booth, alert a BC/EFA volunteer and they will hold your spot in the line so you can go to the photo booth and then come back in line. If you are currently getting your stuff signed and someone is missing because they got called away to the photo booth, they will usually let you step aside and wait for them to come back. Absolutely no photos are allowed at the signing table. You can go as many times as you want throughout the day but you must re-pay for each group of celebs.
PHOTO BOOTH
The celebs are chosen for the photo booth based on popular request. You may be out of luck if someone you want a photo with doesn't have enough people asking for their photo. They only have under an hour for each group and while they try to accommodate all requests, they are obviously going to go with the most popular celebs if given the choice. A photo with a single celeb is usually $10 and they sometimes have VIP booths set up that are $40 and have either full casts or very famous people. If you want a combination that hasn't been pre-announced, you can ask a BC/EFA volunteer and it will be up to the celebs. One year, Anthony Rapp and Jesse L. Martin were both there and someone offered up $75 for a photo with both and that became the asking price. To request a celebrity, head over to the photo booth area about ten minutes before that hour's celebs are set to arrive and there will be somebody very noticeable tallying up requests. Then they'll call out the name of the celeb currently in the booth and put up a sign as well and everyone who requested them will get the chance to get their photo. You can get a picture with your own camera (a volunteer will take the pic) and, as of last year, they were still doing Polaroids for the same price but I'm not sure if that film still exists. With the Polaroids, you also get a cardboard frame and usually the celeb signs it too. Sometimes the celeb will sign something quickly at the photo booth but it's usually frowned up since the goal is to raise money.
GENERAL FLEA MARKET
Shubert Alley is also covered with booths for all of the shows and general theatre-related merchandise and games (e.g. Seth Rudetsky, Playbill, poster frames, raffles, etc.). The price of merchandise depends on what it is so there's no approximate price. Some places have playbills and baked goods and old costumes for as little as a quarter, some have signed posters and CDs for hundreds of dollars. My best advice is always to bring a lot of cash and to bring it in various denominations because in my experience, the ATMs and cash exchange places often have long lines and it's hard to use a credit card unless you're paying for an auction item. I usually split up where I'm storing my cash for the purposes of safety.
AUCTION
Various packages and expensive items are auctioned throughout the day in the center of Shubert Alley. There are pamphlets listing all of the auction items and the starting bids (if applicable). If you want to participate in the auction, just stand near there and raise your hand or your stick when the item comes up. It's just like a usual auction. There is also a silent auction where you write down your bid.
VARIOUS
The flea market is one Sunday a year at the end of September and it's rain or shine. If they're predicting rain, bring your umbrella and your rain boots. Prepare for a lot of crowding regardless of weather. The crowding is worst in the middle of the day and the celeb booth area is always the most congested. For bathrooms, my suggestion for any tourist in Times Square for anything is to go to the Marriott Marquis hotel lobby which is on the eighth floor (note this - it's not ground level). You can go up in the elevator and the bathrooms are on the right. They're clean, there isn't usually a line and it's a way to get out of the heat if it's hot out. Use water, sunscreen, etc. as needed depending on weather. A lot of times you will see Broadway celebs wandering around, including those who aren't part of the celeb table. If you ask them for a photo, some will ask you for a donation in return. Remember that this is about raising money for BC/EFA and AIDS research and not strictly about talking to Broadway actors. If you have the time, spend a lot of time at the merchandise booths because you never know what great finds you will find. Sometimes getting there early when they're just setting up is great because you get first peek and the crowds haven't swarmed yet. It's a great day, you always find great things and meet a lot of fellow theatre fans so enjoy yourself!