Minn has some excellent advice. I've trained a lot of students using the standard Tower Trainer (I also learned using this plane) and it's a good flying plane. It's also an excellent value. You can get the the ARF plane by itself for $69, you can find it here
http://www2.towerhobbies.com/cgi-bin...?&I=LXCAS2&P=0 . You can also get the plane as a RTF (Ready To Fly) for $259 which comes with everything you need (plane, radio, an engine). It actually takes longer to charge the batteries in the radio than it does to get the plane ready to fly. You can find it here
http://www2.towerhobbies.com/cgi-bin...&I=LXCXF4**&P= .
If you're interested in what else is available out there I've compiled a list of available trainers and 2nd planes, you can find that list here: [link=http://www.rcuniverse.com/forum/m_4537845/tm.htm]Looking for a trainer, what's available. (Updated 8-14-06)[/link]
Whatever plane you choose for him please get him in touch with a local club and an instructor. Also, we'd love to meet him. Encourage him to get on RCU here. It's a great place to get questions answered and make some new friends!!
Hope this helps
Ken