One of the best exercises for biceps muscles to start your biceps day is Barbell Curl workout. Most of the exercises are harder when you are lifting barbell instead of a set of dumbbells. The important thing in this workout is to not move your body and your upper hands.
So your starting position should look like on Picture 1. Pick up the barbell, stand still and start lifting it.
Your ending position should look like on Picture 2. While you are lifting the barbell from your starting to your ending position you should inhale. On its way back, exhale, then repeat. Remember, you must lift the barbell with your elbows and keep your upper hands still.