As Michael said, it's a patience game, each step below can take 24 hours or more.
The basic process:
- Preparation (remove mould lines, fill holes, key the surface, wash&dry)
- primer (2-3 coats, 30 min between, cure 24 hours)
- base coat (2-3 coats, 30 min between, cure 24 hours)
- decals (cure 24 hours)
- clear coat (2-3 thin coats, 30 min between, cure 24 hours)
- Polish after a week, or a month
First coat of each step should be a light "dust", then follow up with heavier coats, but not so heavy the paint starts to run.
This is just the basics, before each step you might have to sand down imperfections, and then you also have to wash it in water & soap with a toothbrush and leave it to dry under a "dust lid" before continuing.
With a dehydrator you can cut curing times down to 4-8 hours. I bought a cheap food dehydrator from the big auction site for about 40$, great investment if you like to paint.
Tamiya rattle can's are great, use white primer under light colors, especially red or yellow.