Nothing to it. Really. I had an old Win1200 that was in rough shape too and now it looks great. After the first one, I grabbed another old rifle and camo'd it. Once you get the hang of it, you'll want to camo everything LOL.
1. Scotchbrite the wood to provide a surface for the primer to stick to.
2. Blow it off well. You don't want any dust.
3. Wipe it down well with mineral spirits.
4. Get some Krylon grey primer and give everything a couple of very light coats. I masked off my boltface, front sight,and trigger.
5. Get a two or three colors of the Krylon flat camo and start by putting a light coat of your base color over most of the primer grey. I used the desert tan for my base.
6. Pick out a leaf pattern from some plastic potted plants. Cut one stalk off, trim it up a little and use it for a template.
7. Lay it close against the stock and shoot one of the other camo colors over it.
8. Move it around and shoot one of the other colors over it. You'll get the hang of it pretty quick.
You can use a couple of different leaf patterns for different effects. Believe me, it's easier than it sounds. Make sure that you keep your fingerprints off after the mineral spirits wipe-down for the best finish. Hold the can at least 10-12" away so the paint stays very flat. You don't want gloss. After it dries for at least a day, spray it with a couple of light coats of the Krylon matte clear to protect the paint. You have to keep it about 10-12" away or it will get a little glossy.
The neat part is that you can experiment and come up with your own patterns. Also, it you do nick it or scratch it, it's easy to touch up. Now it won't look like realtree hardwoods but it will do the job which is breaking up the outline and knocking down the reflection.
Here's a pretty good article:
http://www.predatormastersforums.com/riflecamo.shtml
And some pix of other folks paint jobs:
http://www.predatormastersforums.com/ubbthreads/showflat.php?Cat=0&Board=5&Number=52414676 &Searchpage=1&Main=52412725&Words=camo &topic=&Search=true#Post52414676
http://www.predatormastersforums.com/ubbthreads/showflat.php?Cat=0&Board=5&Number=52398598 &Searchpage=3&Main=52398448&Words=camo &topic=&Search=true#Post52398598