I wish I could post a link to my how-to building my 1/72 Defender kit on the old boards. I tried to make it look like a weathered walking tank instead of a robot and had a lot of good tips in there. I must say my models didn't start to come out how I always wanted them to until I got an airbrush.
I will say I like brushing flat enamels and spraying acrylics, go to an art store and buy yourself some good brushes. A really fine one, a medium size one and a large one for doing larger surfaces the finer the feathered edge the better. I know those cheap white Testors brushes and you'd have better luck painting with your toothbrush. The other thing to keep in mind is it's usually better to apply several thin even coats instead of one heavy thick one. Flat enamels dry fast too so you can't overwork the paint. Get it on as best you can then leave it alone.
There's tons of modelling advice about building armour vehicles on the web as well, try google and do a search. Oh and find yourself a good hobby shop, hopefully one that specializes in plastic models. I drive 30 minutes each way to get to the one I shop at.