Mountain Biking - in need of education!

Warning - total newbie, interested in mountain biking, but wanting to learn more before I buy so I don't waste my money. I'm willing to read, talk, learn, etc. I read the "read this before asking questions" thread, which was somewhat helpful. I don't understand some of the terminology, sorry! Any place I can go to figure it out? I know what the forks are, brakes, tires, rims, stuff like that (stuff I knew back in the dark ages when I had a :rolleyes: three speed. Where can I go to find out about the geometry my bike should have, size, etc.? Sorry for asking such basic questions. I just don't want to go into a bike shop and get taken, or make a mistake in buying something. Any help will be greatly appreciated! Thanks!!!

About the geometry thing, you are first going to have to decide what discipline of MTB you´ll ride (Downhill, Freeride, Dirt Jump/Urban, Trials, and Cross Country) then you´ll have to test ride the bike and make sure it fits your needs, if you are unsure what you are going to do a nice all around bike like the Specialized Hardrock (note this is just an example to give you an idea) would do.

http://www.abc-of-mountainbiking.com/images/pics/anatomy-mountain-bike.gif

http://www.abc-of-mountainbiking.com/mountain-bike/mountain-bike-anatomy.asp

this too:
http://www.bikesrnottoys.com/

The geometry of the bike frame will kind of dictate how your body will sit on the bike - the best thing to do would be to visit a couple of bike shops and check out all the different bikes thay have. Make note of which ones "feel" right to you, and then you can research those bikes - plenty of reviews on line, and you can get an idea of what the bike should cost, and what components would be on it. Check places like MTBrev - or just google "mountain bike" and a whole assortment of magazines will pop up. Go to a local race, meet some folks, talk about the bikes.

You Local Bike Shop (LBS) is not likely to try to "take you in", as they will want you to come back for the inevitable upgrades! Good Luck!

YOu are like me. I always want to know everything(bike related or not) I possibly can about something I am buying before I even consider it. It's a good policy rather than just going in and buying a bike and then coming on here and asking, "just bought this bike, is it any good, is the size right, can I do drops with it?".

Chone has it right. Geometry is typically dictated by your type of riding. YOu need to decide on what you want to do with your bike and then the style of bike you need will be apparent. Decide on your price range and look at as many different manufacturers bikes as possible that fit your style and price range.
Unless you have a specific style of riding in mind you are set on, since youa re jsut getting into mountain biking, a "do it all" bike might be your best choice.