Grab a hold of the EZ bar with your palms up and at shoulder width apart. This is your starting position.
Raise the bar up until your forearms are almost completely vertical. Then, lower it back down all the way but don't fully extended your arms (you should always keep tension in your biceps for maximum effectiveness). Finally, repeat entire movement for the desired or prescribed number of repetitions.
Perform this exercise in a smooth and fluid motion
Keep your elbows tucked-in and close to your body
Don't extended your arms completely on the downward portion of the movement
Don't swing your body in an attempt to lift the weight easier; this is cheating and does nothing for your biceps
SPECIAL NOTES & LEVEL of DIFFICULTY VARIATIONS
To increase the level of difficulty, slow down the movement or load the EZ bar with more weight.
This is one of the all-time classic exercises for the biceps. The advantage of the EZ bar is in its comfort because it's low impact on the wrists and the grip angle feels more natural. Thus, for those people who have problems with thier wrists, this exercise is especially usefull.
One item worth noting is that it's very important not to swing your arms up. This is cheating and will render the whole exercise less effective and will also put unwanted pressure on your lower back. One way to ensure that you keep yourself "honest" is to stand up against a wall and then execute this movement.