First off I would like to thank anyone that takes the time to read and reply to this post as it is very helpful to me. Ok now to the questions: I am currently in my first semester of college and recently got back into lifting(I have lifted off and on for the past few years but never kept steady at it) My workout buddy takes NO-Explode and said he loves it and it gives him a huge increase in enery and pumps. I have also become interested in it and was looking at not just NO-Explode but the whole stack program (NO-Explode, Nitrix, Cellmass) The only supplement I am currently taking is Designer Whey protein, 3 times a day. Do you think it is worth it to buy this program? Do you think these 3 are essential or should I add more? Should I continue to keep taking Designer Whey along with the Stack program if I get it? How many days a week are optimal to lift? (I currently try for Mon-Fri but sometimes things get in the way) Also, when I'm on the off period I have read about do I quit all 3 supplements for the 6 month or so rest period or only a few and should I just go back to Designer Whey only at this time or anything else? One last question, sorry, What exactly do I have to do for the tolerance testing I read about on the back of the bottle? Thanks again for all the time, I very much appreciate it.

Yes, it is worth it to buy the program. Personally, I would just start out with no-xplode and see how much you like that.
 
Whey is just protein that is absorbed really fast. And is convienent. It is best right after your workout and to supplement your protein intake if you can't eat enough during the day. Your body needs protein just like it needs carbs and fats. While your lifting you need more protein (hence protein supplements).
 
The three supplements in the mass stack work together very well but are pricey. They are basicly:
no-x - pre-workout (stimulents, a bit of creatine and some nitric oxide pre-cursursers)
 
nitrix - all day - even more nitric oxide pre-cursers
 
cell mass - more creatine for after workout/before bed
 
Keep taking your protein, these three supplements have no protein in them.
 
4-5 days a week is optimal. Depending on your training split. But give yourself at least 2 days rest.
 
From personal experiance I would say that the mass stack is effective. If it is worth the money or not is up to you.
 
There are cheaper alternatives out there (search the forum) and a zillion other supps you could be taking. But if your just starting out then I would keep it simple.

If you were like me in college you needed the budget plan though...  ALTHOUGH the products are great.. if you need a budget plan, check out this the Muscle and Fitness, it might have been last months though... 
 
GREAT budget prices on supplements, especially for college students... 
Just be careful where you buy, you can end up paying over $130 or more for the stack... I suggest stock up online for free shipping if you get it.