This question will undoubtedly get a gazillion different answers, as everyone has their own favorite paint type and/or brand.
I'll make it very simple for you: There is no need to mess with 2-part paints or any of that esoteric stuff. Modeling is supposed to be fun, not a chore! Here is a simple rule to live by:
Enamels: BAD! Take too long to dry, both sprays and brush paint. No reason to even mess with them. They are yesterday's technology.
For brush painting small parts and detail painting: Acrylics. Water-based, non-toxic, available in tons of colors. Simple brush clean-up with nothing fancier than plain old H2O.
For spraying: Either lacquers or acrylics. Both go on nice and smooth, both dry fast, they are not prone to runs and sags like enamels are, both can be either clear coated or polished out beautifully. I personally prefer DupliColor automotive touch-up sprays, available at any auto parts store.
One simple rule to remember: Don't use enamels! Believe me, your life will be much simpler and happier if you stick to acrylics and lacquers.