Lastly, of the reasons many don't want to use an airbrush is the cost. Yes, I have spent much on my Badger which is a great tool. But honestly, my everyday workhorse is the cheap $20 airbrush I purchased at WalMart that was made for them by Aztec. It is a single action "Plain Jane" that is simple to use, clean and maintain. OK enough of the reasons why you should make the switch, now for a few very simple basics.
I shoot mostly solvent based paints like Floquil and Testors but on occasion, like to use lacquers and acrylics. The solvent based paints are very simple to use right from the bottle and a one ounce bottle can last for a dozen models. I do not use the rather expensive thinners offered by the manufacturers for these since I can use regular turpentine or paint thinner bought at the hardware store at a substantial savings. I often shoot directly from the bottle without thinning depending on the viscosity of the paint. For any kind of paint, it should be the consistency of whole milk. When you swirl the paint around in the paint cup, it should cling to the sides but be translucent as it slides back down to the bottom of the cup. I thin and clean the airbrush with the above mentioned thinners. I should at this point mention that I often take spray can paints and decant them into my paint cup with a straw. None of them ever needed thinning as they are meant to be sprayed anyway. After I'm finished painting, I run clear clean thinner through the brush, disassemble the cup and head from the air line and simply wipe any excess from the parts. In over ten years, with the current brushes I have, I have never completely disassembled an airbrush to clean them and they are all still in good working order. If it looks like I have a lot of build up of dried paint anywhere, I simply drop everything in a tin full of lacquer thinner for a few hours and everything comes out looking like new.
The Mack Vision above is example of an automotive lacquer. Lacquers are equally as easy and the same rules apply for viscosity and cleaning except to substitute lacquer thinner for the thinning and cleaning process. Nail polish fall into this category too and the colors available there are amazing. I often go to the cosmetic counter where a basket of bottles of nail polish that don't sell well for fingernails will be as cheap as 2 for a dollar. The only draw back to lacquers is their propensity to dry too quickly coming out of the airbrush. Sometimes it will give a gritty look to a model as the paint droplets in the spray actually dry before they hit the model. The solution to that is to cut down the distance from the airbrush to the model. Drying in the orifice of the airbrush can also be a problem but thinning a paint further usually fixes that.
Acrylics behave similarly to lacquers in that they dry very fast and pose the same issues as lacquers. My opinion is that one needs to use good acrylic paint for the airbrush and don't go with the cheap craft paints like Apple Barrel and Folk Art. They have their place but not in the airbrush. My favorite in acrylics is the line produced by Vallejo which is what I used on the F850 above. I thin acrylics for the airbrush with Windex. And clean my airbrush with windshield washer fluid that can be bought by the gallon cheaply. One note, when I clean my airbrush after shooting acrylics, I wait a few minutes and then shoot some lacquer thinner through as well. Sometimes there is a chalky residue leftover from acrylics I want rid of.
With the airbrush, I have never had some of the conflicts of the spray can use like orange peel finishes or runs and drips. The airbrush process is just so much easier to control. So go ahead, buy a cheap airbrush and give it a whirl. Experiment with all kinds of paints since your experimentation will yield much more information than I could ever hope to give you. And don't wait another day to tell your loved one's you care.