You can learn a lot about tuning, repairs, waxing, etc on you tube. Try googling base repair and whatever else you need to learn. P tex repairs are very easy, you just need a Ptex candle and a metal scraper. The best way to learn is to do it yourself, soon you will be a master and you can avoid expensive shop tune ups. BTW stone grinds are rarely necessary, they are only needed when your base is thrashed, which won't happen too often because you will be on top of your own maintenance.
It takes an investment to build your tuning kit, but considering how long you will be using it, it will save you money in the long run. Check out these websites: racewax.com and skifastwax.com. I also think its fun to tune my board. Crank up the tunes, drink a cold one, and blow your friends away on the mountain. Good luck.