Souda - Every guy should hope for a wife that gives gifts like an airbrush, (best keep her happy, she's a good 'un.)
What airbrush did you get? Regardless, one of the major considerations will be the handling, cleaning and overall maintenance. I recommend thoroughly reading and understanding the manual, then some practice at taking it apart and re-assembling. That will help you understand the inner bits.
You might try a couple of different paint types, acrylic and enamel, to see which you prefer. I use both types, but for the most part I still use mostly enamel. It's disadvantage is the stronger smell, acrylic is much more friendly for use.
And I absolutely second the recommendation to have a thorough look at 'Don's Airbrush Website,' just so much valuable information. You'll gain a lot of knowledge, by having a good look there.
Good luck with it, and please check back in with your results after you get on with it, we'd all like to know.
Patrick