Alot of people like to start their bicep routine with heavy barbell curls, but I actually like to start my routine with an exercise like a 1 arm machine preacher curl or a seated incline dumbbell curl. The reason being is that I like for my biceps to be warm when I start doing heavy barbell curls. I credit the incline dumbbell curl for building my peak. Its a very simple exercise, but if done correctly will work wonders for you because it allows you to get a great stretch on the bicep head and you really cant cheat. From there I go into a barbell curl (usually with a straight bar or a close grip EZ bar). I credit the barbell curl for the strength and over all size of my biceps. I like to maintain strict form when training biceps. Dont ever swing the weight up. Power the weight up with your biceps, squeeze the peak, and lower the bar slowly. Its okay to slightly rock on the last rep or 2 but no more than that. From there I like to do a hammer curl with either a rope cable atatchment or dumbbells. Both have the same benefit, but the rope cable hammer curl will keep constant tension on the biceps and will make it more difficult to cheat. This exercise is great for targeting the lower portion of the peak and the brachialis. From there I like to end out with either a preacher curl with the EZ bar (or a spider curl). These exercises are great for packing on mass to the peak. If you need to work on the outer head more then favor the inner grip and if you need to focus on the inner head more favor an outer grip. It doesnt take a lot to demolish the biceps and they are a very simple muscle group to train so dont go over board. typically I do 4 sets of 8-12 reps per exercise.