If you're just checking out the programs for the first time, you might wonder about the best order to progress through them. Here's my suggestion:
Start with Unf*ck Your Program. This will teach you how to adjust the other programs to best fit your body and your goals.
Next, try the powerbuilding programs. These are ideal for adding size and strength; obviously, you'll want to begin with part 1, the 12-Week Powerbuilding Program, and then move to Part 2, INTENTsity.
By then, you're ready to peak, so bust out the World-Record Peaking Program. This is probably the most physically demanding of the programs available, so I suggest saving it until you know you're ready to test your limits.
Hope that helps!