I used to do a fair bit of miniatures painting. Suggestions:
1) Sit down with your figs and clean'em up first: remove flashing, mould lines, etc. A sharp X-acto knife and a small file will suffice.
2) After that, mount them on the bases. I liked epoxy, because you could get a little more support. Some people use epoxy putties or cyanoacrylate glues. Pick what you can work with.
3) PRIMING. Prime with white or pale grey. I find it works better for most things. Really, priming makes a world of difference.
4) You'll need a good array of colours in matching palettes - a set of warm tones, a set of cool tones, and varying saturations. This will help you layer up, add depth, and make nicer paintwork.
5) You may wanna read a few techniques, try what you think you can master easily. You can get more complex with practice. Here's a decent place to start:
http://minipainting-guild.net/
6) Last but not least: If you try to base your designs on real-world things, you'll get better results. Seriously.