Muscles take time to grow my man... there are 100's of different plans out there to help you get bigger. For me, my arms tend to grow the more I do heavier compound movements such as deadlifts or barbell rows and squats... believe it or not.
I really only do about 3 exercises for biceps... once a week... but it is enough to work them considering what I put them through in my back workout.
Switching up your workouts... making sure to do some low-rep, high weight exercises... such as the 5x5 -- do a weight you can only do for 5 reps or so for 5 sets... you'll hit your LARGER muscle fibers when you do reps from 3-5 at a weight you can only do for that amount.
Too often I see guys going in an curling weights for 12-15 reps... it will only hit their smaller... slow twitch fibers... increase endurance... some growth, but not a substantial amount.
C-ditty