All good suggestions on balancing and CG. But please read my post below on the GP PT-40 trainer - I have some experience with this. Please make sure your plane balances on the wing spar! I found that the plans and instructions are incorrect. Above all get some help at your local club. Have an instructor check out your plane, check the CG and perform the maiden flight.
Good luck. BTW, you will love the plane once it's setup correctly!
http://www.rcuniverse.com/forum/m_58...tm.htm#5823388