Go to your local auto paint supplier, and talk with them about the products they sell. Tell them you are looking for an easy to use paint system (usually some sort of urethane), that isn't overly expensive. I like to use single stage paints that are compatible with being clearcoated. Basecoat/clearcoat 2 stage paints can be a little more complex to use because of the timing requirements, especially when you are doing the work in your garage. Even a single stage auto paint will be fuel proof for nitro. I've been using the BASF Limco system with good results. The HOK paints are excellent if you want exotic colors and are airbrushing small amounts (like doing graphics on motorcycle helmets or tanks, etc.), but you can have the local shop match colors for you and get great results with less expensive products. You will need a good, high volume air compressor, a decent paint gun (ideally, a full size gun for priming and clearcoat, a touch up gun for color, and an airbrush for small areas and fixing goofs). As far as the paint materials, you will need a two part (hardening) primer, paint, hardener, reducer, and clear and clear activator if you are clearing it. It can be expensive, but when doing helis, you will end up with lots of paint left, and build a 'library' of colors eventually, and the products last a long time. I'm still painting with some stuff I bought three years ago.

Here's some examples, all were done with basic auto paints in my garage: