Mike, flint and obsidian are both extremely high in silica. The difference is in the way they are formed. Obsidian has a volcanic origin, while flint is formed in chalk beds. Chert is formed in limestone and otherwise can be very similar to flint. If that isn't confusing enough, then you have jasper, agate, chalcedony, chrysoprase, opal, and a gob of other materials in the mix. Luckily for dweebs like me it's worlds of fun sorting all this out.
There are several books on knapping, but it's a darned hard way to learn. Knapping is intensely visual and 10,000 words are needed to describe a 30 second technique. I'd recommend you try a DVD or video. Several sponsors (Raptor and 3Rivers) carry some very good ones.
Not sure which Hope and Paradise you're between, but there may a knap-in near you. Sitting with some experienced folks is far and away the best way to learn. Plus you can get tools and stone at the same time. It's usually BYOB, though (bring your own band-aids). GGG