Joshheat25, if you have built furniture or worked with wood, you should do fine. Nothing much different with gun stocks, really.
1. As to stripping, it depends on what you are refinishing. Over the past few years, I have refinished the laminated stocks for a Romy AK, the plain wood that came on the same AK, the walnut on my 10/22 Sporter, the plain (blah) wood on my Iver Johnson M1 Carbine and a couple Yugo Mausers. On all, I stripped with CitriStrip. CitriStrip is a chemical stripper but isn't very harsh, like Zip Strip. If the wood is oil soaked (my Mausers), I've had good luck with CAREFUL use of a heat gun to heat the wood a section at a time to leach out the oil, then wiping it of with mineral spirits. If the gun you want to redo already has a finish, you'll likely have to strip it.
2. The finish. Basically, it all depends on what you will use the gun for. On an outdoors gun, polyurethane might not be a bad idea. Personally, I HATE poly, but it holds up REAL WELL to moisture. I've tried Tru-Oil and don't like it at all. Looks too "plasticky" to me, same as poly. I've had real good luck with REAL tung oil. Not a tung oil "finish" (which are mostly varnishes and linseed oil that mimics a tung oil finish), but PURE tung oil. Thin the first few coats 50/50 with mineral spirits or turpentine, rub it on, let it dry an hour or so and wipe it off. Let it set till it dries/cures and go at it again. After the first, oh, 3 or 4 coats (maybe more, enough to seal the grain pretty well), wipe it on full strength, let it set an hour or so, wipe off the excess, let it cure and keep going. When you start wiping on full-strength coats, it may be necessary to steel wool between coats if the finish looks "blotchy", which means it soaked into the wood in some areas and sat on the surface in others. Keep going till you reach the desired level of gloss, LIGHTLY steel wool one last time, then finish with a coat of Johnsons Paste Wax. Looks VERY GOOD (to me, anyway), pretty durable and is easy to touch up if the stock gets dinged. Only drawback is the time involved. It took me about a month to finish each of these stocks, the vast majority of the time was spent on waiting for the finish to cure before moving on. Only takes about a day for each coat to cure but it adds LOTS of time. Here's my 10/22 with tung oil.
It's really not as glossy as it looks and has a warm glow to it, not at all "plasticky"-looking like poly.
Good luck with whatever you decide. Just remember, take your time and, like most refinishing projects, finish preparation is EVERYTHING! Even the best finish can be ruined by hasty finish preparation.