Clueless questions
Sblaze,
I am in your area and would be happy to help you out. There are also a number of clubs in the area to get help from.
To get started, I would HIGHLY recommend purchasing from a local hobby shop. They will be there to answer your questions. After he gets into it, he can start ordering mail order.I know of two hobby shops that everyone seems to frequent, one is Doug's in Waldorf, Md (I haven't been there personally), and the other is Hobby Hangar Speedway in Chantilly, VA...out by Dulles (I go here).
As far as planes go, there are a number of options, I recommend somthing with a semi-symetrical wing as opposed to the typical flat bottom wing you find on most trainer type planes. The semi-symetrical wing, with a high wing configuration, will serve as a trainer but will also allow aerobatics as he progresses.
To answer a few more of your questions, ARF vs needs to be built. This depends on him. Does he like to take the time to build somthing, or is only interested in flying, or would he like to get flying, but then begin building from kits? Since you said he likes the CG chipmunk, I am guessing he is not afraid to build.
One option for you, is to purchase a gift certificate from the hobby shop of choice so he can make some of the decisions (It will be awful hard to be sneaky and find out the information you want from him).
Please feel free to PM me with any specific questions. I have been in the hobby for 20+years, and therefore have many useless opinions!