Before you go rushing out to buy supplements, check out the archives at
www.leanandstrong.com.
More recommended reading is at
www.hussman.com/eas as well as the "Body for Life" book (but you already have that, right??)
Supplements (I don't put "Meal Replacement" shakes in that category BTW) are NOT required. And what you MAY want to use you can get MUCH MUCH cheaper elsewhere than EAS' website (which is also
www.bodyforlife.com). Try
www.netrition.com or
www.vitaglo.com for starters. But first, go to Lean & Strong...read some of the archives, the libraries (Training library - check out Pam B's new post there!!! Awesome!) and the transformation pix...
Here's what I use (remember, all this stuff is OPTIONAL!!):
Myoplex Lite (I buy the 42-serving Neopolitian Variety Pack - muy cheapo!). Don't bother with the RTD shakes and the bars. They taste like ca-ca!
Most women should use Myo Lite since it has fewer calories than regular Myoplex (a nice bonus - it's also cheaper!).
Glutamine - (Labrada Glutamine 1000 is the best buy). Don't waste your $$ on CytoVol (EAS' version). Also stay away from the capsules - you'll have to take a ton of them to get the same serving size as a scoop of Labrada.
Multivitamins (I buy mine from Trader Joe's but you can just go generic on these - no need to spend a lot of $$ on fancy-schmancy ones).
Udo's Choice Perfected Oil Blend - or any good EFA product out there.
Creatine - just use the cheapest generic powder you can find. I mix mine with Tang, water, and my serving of glutamine and slug it down three times a day.
You can do the BFL program without using ANY of these products but I'd definitely at least do the Glutamine and the Myo Lite (or a comparable meal replacement - gets hard to make 6 meals a day!)
Oh, Susanje would say - stay AWAY from the scale during your Challenge. Instead, take measurements and 'before' pix (as painful as that may be to contemplate - you'll be glad of it 12 weeks from now!)

before beginning the 12 weeks.
I'd also recommend - for the first week anyway until you get your bearings - posting your daily menu at
www.leanandstrong.com. Tall Jen (TJ) has a daily menu thread that she starts about 10 a.m. each day. She'll give you an honest critique of what you're eating and make recommendations!!
See ya!
PS - Just re-read your post, and I guess you're signing up for the Challenge officially - while the rules state that you MUST use EAS products in your challenge, you do NOT have to buy them directly from EAS. Save yourself a small fortune and go to
www.netrition.com or
www.vitaglo.com. Oh yeah, it doesn't say that ALL your products need to be EAS either so if you just want to use Myo Lite, that would fit the requirements of the contest. Just save your receipts!!!