for the top case, the easiest thing is masking. Check with sign shops, custom paint places, etc. is good too. You can get rolls of medium tack masking tape that are ten inches wide, by about 50 feet long (its what I use) which means you can get a good coverage, without tons of overlapping tape, which sucks.

As far as painting itself goes, heed eulaca's warning. Always keep your cleaners, solvents, chemicals, etc, AWAY from your surface, or your painting area, unless you are using specifically THAT product for a specific reason. Likewise, clearcoat your work when done. That way you can wet sand it to a mirror finish, and the clear will protect the paint from blemishes, etc.
Electricity tastes good. No, seriously.