Re: what kind of paint
well since no one else wanted to chime in.... You'll want to use a primer specifically for aluminum - zinc chromate usually, but there are newer formulations that would also work. Oil based paints react w/ bare aluminum, so I've heard.
On top of the primer, use Rustoleum, a "marine paint", or whatever else you're comfortable with.
The "search" function will give you a ton of info about all this, too.
