Bicycle Mechanics - rebuild purchase

Im thinking of buying a used road bike to experiment and learn on how to do mechanical work on a bike. Any suggestions on what to look for? Probably something somewhat modern, so that I understand how to work on modern components. Im looking to find something that I can do a total rebuild on as a way of teaching myself how to work on all parts. any suggestions welcome. THANKS!!!!:)

I wouldn't bother going for anything new-ish. The basic principles will be the same. Cables tension, chain maintnance, bearings, etc. may have evolved a little but they are the same basic beasts. I would look for a nice steel framed bike from the 70's or 80's. They can be had for reasonable prices. When you are done, you will likely have a cool bike.

Would there be a good name to look for and what price range should I be thinking?

Most manufacturers will have offerings from classics to junk, so name brands can be a hard one as a guide to buying old bikes. I would look for lugs at the joints of the tubes, forged rather than stamped rear dropouts (here is a link to some pics from Sheldon Brown's page to see the difference: http://sheldonbrown.com/gloss_dr-z.html#dropout), and stickers that identify the steel as 531 or Columbus (lighter alloys of steel).

Prices can fluctuate wildly depending on your luck. I would set a budget for yourself (including tools) and then start combing Craig's List and yard sales until you find something you like. I got a pair of old Raleighs for $20 this summer. There are deals to be had if you keep an eye out.

Since I havent had a road bike as a "grownup" what is a good way to judge size? Should I take this on without going through the new bike fitting and getting a good feel for a bike or should I be able to get the correct size road bike without too much trouble? I could also buy a beat up mtb and do a rebuild of that since I have been on one before? Im about 5' 9 1/2" but I know that doesnt always make it an exact science for sizing.

Also, anyone know how to mend torn spandex shorts? I have a hole in my shorts just big enough to put a finger in.