the ultimate warhammer 40k painting guides is what you would want to google, followed by .torrent if you didnt want to pay for a good book on painting figures and miniatures =P

As far as creating a chipped paint effect, get a sponge, get some silver (or whatever color you want the chips to be) and put a very very small amount of it on a small area of the sponge, when i say small amount i mean hardly any at all. What you want to do is dab the sponge on your desired area quickly, pushing down and kind of rolling your finger to pull the sponge in one direction, if you just dab it on the area it will just blotch, if you roll it will give an uneven chipped effect. Practice on a spare piece of cardboard or a plastic milk bottle or something first.

The thing to remember with transformers is if your going to transform them then most water based paint (like games workshop) will chip or ware off when you transform it. you can get clear spray varnish to seal the paint, i think most craft stores have it in gloss or a matt finish. I've painted all different stuff over the years, if you have any questions just ask.