Huh, new sub-forum? Well, I'll start out posting some info for people looking for information.
There are a number of mountain bike trails in the ozarks, and the best place to find em is generally http://trails.mtbr.com/
In my area, (that is, around Lake of the Ozarks and FLW), the best trails are Honeyrun (LOSP), Trail of the Four Winds (LOSP), St. James MTB Trail, Rolla Lions Club Park, Berryman Trail, Bittersweet trail (Osage Beach) and a number of others near Springfield.
There are bike shops in Rolla, St. Robert, Springfield, Osage Beach, and Jeff City that I know of (and obviously STL/KC).
I've been mtbing around here for years, so I can generally point you in the right direction if you've got any questions.