I like to use black spray primer and then do some pre-lighting with white spray paint from above the miniature. When its dry it gives a really nice backdrop for your paints. Just soak the spray cans in warm water so they spray smooth. You also want to be about 2x as far away with the white and just lightly dust it on.

Be sure to thin your paints, 100 really thin coats is way better than 1 extra thick coat.

I personally don't use painting handles, I just super glue one end of a toothpick to the bottom of the mini, and then break it off when I am done. This method is pretty delicate, and may not work with very heavy minis or rough handling. The bottom of the base isn't incredibly important to paint, IMO.

In terms of simple color schemes, the easiest is of course solid colors, or if you want more than one color, to use large parts to pick other colors. For example, an all blue body with chartreuse arms. Once you start to get the handle on painting small, you can do much more elaborate schemes and weathering.

Keep in mind, your first minis will be bad, but that's okay because everyone's first minis are bad. Even professional mini painter's first minis were bad. As all things that take practice, you will not be happy with your first minis later down the line. So if you have a mini that is particularly rare, or one you really like, I would avoid the temptation to paint that one until you are satisfied with your skill in painting minis.