CG is the point at which the plane should balance when supported by two fingers or dowels.

Normally the manufacturer recommends a point to be measured from the frontal edge of the wings.

If the plane is out of balance, it cannot fly properly.

Especially after you have glued the broken parts together, you need to verify that the plane balances at the recommended point.

Second, you need to verify that the control surfaces deflect in the direction that you command them to deflect via your transmitter.

I also back up the advice of seeking experienced help.

Read this article about how to balance properly:

http://www.rcuniverse.com/magazine/a...?article_id=84

Best luck with your learning curve, Brian!