Mopauly,
Woody and Hou have the answers - Badger, Paasche or Iwata are really the only choices - they make very good quality air brushes and it's easy to get spares for them - do yourself a favor and spend a little more than you think you can afford, as later, when you get more skilled, you'll appreciate the extra features of a more expensive airbrush.
Get an internal mix, single action (like the Badger) or get a double action.
The single action basically has an on/off switch for the air, and you can dial in the amount of paint you allow through the gun, using a knurled knob at the back of the gun.
The double action is a little harder to master - you rock the trigger backwards to increase paintflow, and push the button down to increase airflow. This can be tricky at first for a beginner.
Shop around for the best price - there's hundreds of sites online - or try a well stocked hobby shop. Ask the guys in the shop which air guns they use - some hobby shops even run airbrush clinics to teach people how to spray. Maybe someone local can give you lessons. Just ask around. They can be a wealth of information and help - they can help you avoid making the terrible mistakes I made when I was starting out.
Cheers,
LeeTree