Weight Lifting Question for anyone who is knowledgable in the area.?

I've been lifting for almost 4 years now. Im about 5'11 and 200 pounds and i'd estimate about 10-11% body fat. I do your standard, Bicep-back, chest tricep and a third day of shoulders and abs. I also eat about 40 grams of protein immediatly after i get home, either in a shake or eggs and milk. Im trying to lose a little more body fat while adding more muscle but i've hit a wall with my workout. (i increase weight and do sets of 10-8-6) I no longer see improvements and ive been stuck at the same weights for quit some time. I also don't take any supplements because i don't know what to take. I was wondering if anyone could offer any insigts, new workouts, or supplements that can assist me