In my opinion supplements aren't really needed I wouldn't stress over it. I would just concentrate on perfecting my diet and any supplements that will help do that, for example bars to eat when your on the run,or protein and carb powder post workout,all you really need is food supplements. And a muiltvitamin is good. But other than that, its not really important, maybe thermos are good,possibly creatine depending on you. Their are a few other ones too that may be worth trying,but the cost of using them is alot,and they'l probably bring mininmal results compared to a good diet. Few other supplements may be useful in certain cases and for certain periods of time.
also these are over the counter supplements,not steriods, so any anabolic gains you will make from non food type supplements will be very very minimal,especially compared to gear, In the number 1 supplement over the counter is food and your diet( i know it sounds stupid ) ,its cool to take creatine and stuff,but the number 1 thing to concentrate on is your diet in my opinon