i you do use paint, i would reccommend tamiya model paints, they are some of the best quality that i have seen and used and they dry very quickly. also use a very very fine brus, like only a couple strands for detail work. i will be the first to admit, i suck at painting, but the lego stuff i have painted came out pretty well. just take your time with it as well.
I paint in details on my Minifigs, but I generally keep it simple because this seems to work best. I've never tried painting bricks in solid colour though and I'd have my doubts about this unless it's a MOC that's going to be a permanent assembly.
Zahru II wrote:As a purist I'm terryfied even of the thought of painting bricks, but I suppose your best bet would be that kind of paint that can be easily removed (acrylic? idk).
One thing that I tried was using masking tape and putting them on minifigs then coloring the masking take with a permanent marker it worked pretty well and can be used to make lots of different minifigs seem similar.