I've been refinishing and restoring for several years now... I agree that you should start off with a relatively cheap (price wise) mil-surp like the Mosin Nagant 91/30.
You will learn as you go on what materials you'll need or want to have to make the job easier... I also suggest you get a decent camera and take plenty of photo's as you go. Nothing worse than tearing a rifle/pistol down then forgetting how it went back together again..