RE: Any flint knappers out there?
Make sure you check your State laws because I know in MN, they state that legal tips must be at least 3/4'' METAL and sharp!! Theres no dought on the sharpness of and Kapped arrow head, you should see how that stuff cutts through leather!!
As far as getting started I'd say to buy a video or find someone to show you! It would be pretty hard to learn from a book!!
Some guys do use glass grinders and such for shapeing points, makes the job alot easyer, but some consider it cheating!
I've made a few arrow heads out of different cherts and a few out of glass. Glass works almost just like obsidian!