Train Hard. Recover Hard.
That's the first thing you need to know. If you think you're going to build arms by skipping meals, you're in for surprise. You have to eat big to get big.
Now that we got that out of the way, lets talk training. The arms is one of the first muscles people notice. However, often half of the arm is neglected. When was the last time you saw someone training forearms hard. Never. Keep in mind, your forearm is what creates your grip. Make sure to maintain that strength or you'll find yourself using a wrist belt to do pull ups.
Lets get to business. Triceps and Biceps. These two make up 2/3 of the mass in your arms. This issue will cover Triceps. Your next report will cover Biceps. Stay tuned for more info on that.
Triceps. Located on the back of the arm. Three muscles total. The most powerful muscle on your arm. Typically a well formed tricep shows not only the long head (the massive part) but also the short head (the part that gives your arm that cut). The long head is the largest, so train that first. Here's some workouts that blast that area. Make sure to put so much weight on, that your only able to lift 8 times. The Tricep can stand a beating, so shoot for 12-16 sets.
Tricep Long Head:
Tricep Short Head