Plan the supplements you integrate into your program around your specific goals. Tailor a plan to your needs.
Step 1: The Base
The base of your regimen should consist of essentials, like vitamins, minerals, antioxidants, aminos and the like. Therefore, start with a potent multi like Animal Pak and a good protein powder. This is true, regardless of your specific goals.
Step 2: Specialization
The next level of supplementation requires specialization. Consider additional basics like creatine (Animal Pump) and maybe a weight gainer like Real Gains if you're looking to add size or a fat burner such as Animal Cuts for an athlete looking to burn bodyfat.
Step 3: Targeting
Beyond this, there is another level of specialty supplements which should constitute the icing on your supplement cake. For maximizing anabolism post-workout, for example, you could add Animal Nitro (EAAs). For increasing the efficiency of your calories, you could introduce M-Stak. For a natural hormone booster, you could consider Animal Stak 2.
As you get more sophisticated, you can layer supplements on top of one another. In sum, the more advanced you become and the more specific your goals, the more complex your supplementation should be and conversely, the more general and basic your training goals, the simpler your supplement approach.
For more info, check out Punisher's "Designing A Stack 101":
http://forum.animalpak.com/showthread.php?t=257