I'm really new to woodworking, and am building a small table. I've
gotten quite a ways into the project, but I can't decide how best to
flatten the table top. The top is a sandwich (don't know what you
wood folks call it!) of oak and some other cheap wood. However it's
got a bow in two dimensions, and I'm not sure how to:

(1) Take the bow out of the wood.
(2) Keep the wood from bowing again.

Your suggestions are greatly appreciated.

Thanks!
Emil