whey protein is the most important and at your stature if your really serious i would go 1.5-2grams per pound of body weight per day. i also take GNC's megamen's multi-vitamin pack in the morning (glutamine, nitric oxide and other minerals) and creatine monohydrate (5g per day). i cycle this 2 months on one month off.
there's a tremendous, tremendous website about your overall diet here:
Everything You Need to Know about Bodybuilding
it covers everything from your workouts to sleep to your diet to supplements. i took the sample diet that's given by the author and adjusted it to my custom stats and have been very happy. he explains everything very well and can get you started on the right track.
AZK's post is dead on accurate as effectively gaining lean muscle mass requires a complete lifestyle change. supplements are the least important component of that change. keep that in mind. this doesn't mean it can't be fun and exciting. good luck...
G