need links for general geology Options

[dbx]

I've looked through several links; none really get me what I think I need.
I guess I'd like to be able to identify different rocks, so when out on a hike,
I don't walk by something unique. And I tend to hike way out of the way places,
not likely anybody's' claim. I think interest comes from a trip to Colorado School of Mines
Geology Museum and realized the vast variety out there. And, yes, I watched a couple
shows of the gem hunters on the weather channel. ( they're characters, for sure )
Also, is there a central place to check for existing claims - easily ?