The World's most common (and its variants) Assault Rifle. If you care for the particulars go here.
Here is a quick reference on how to make it go bang.
1. The Trigger. The AK is often found in its select fire model, meaning it can fire semi-automatic or full auto. To make a loaded rifle go bang you squeeze this.
2. Location of the Safety Mechanism. You should never walk around with your finger on the trigger regardless (Rule 3 of firearms safety. Keep your finger off the trigger until your ready to fire). However you don't want to engage in a fire fight only to find that the safety is on. The safety on the AK is the lever shown in the picture above. The lever all the way up (like in the photo) means the safety is on. Lower it all the way down and it will fire one time for every squeeze on the trigger. Put the lever in the middle and it will fire full automatic (on full auto variants), meaning if you hold the trigger down the rifle will keep shooting until the magazine runs out of ammo or you take your finger off the trigger.
3. The magazine release. Like the trigger squeeze on this and the magazine will come out. It may need some help from you to pull it free.
4. The Bolt. If the gun is empty and you put in a fresh magazine pull the bolt back and let go of it. This will chamber a round. As long as the gun functions well (and AKs function well) you will only have to do this one time per magazine.
5. The Magazine. Generally holds somewhere between 20-40 rounds with 30 being the most common. When putting a fresh loaded magazine into the rifle angle the magazine forward into the magazine well, then pull the magazine into the gun in an upward rocking motion.
6. The rear sight. It shaped like a V for the general sense. It has a notch in the middle. You visually align the front sight into the notch. If you have time line the front and rear sight up so they are as close to even on the top of the post and notch as possible. If you don't have time, guesstimate and fire off a couple of rounds and adjust as necessary.
7. The Front Sight. This is the rock that the church is built on. When shooting (again if you have time) focus your eyes so the rear sight is fuzzy and the target is fuzzy and the front sight is clear. The front sight on an AK is generally a center post.
