Cmk10: Don't listen to Bicoastal too much. The world revolves neither around him nor seasoned MileagePlus 1K's. I'm a high school student too, and I made Gold this year flying mostly domestic itineraries. There's a good chance I'll be Platinum in a few years, if I pick up with the international travel again. Anyway, I've found it's pretty easy to get upgrades with Gold Status--if you're willing to pay for them.
Do check out www.aa.com...they have very good information resources. In addition, AAdvantage will be mailing you a "Gold Information Kit" (or something to that extent) that willl explain the status' benefits to you.
Lastly...how the hell did you get to Gold with only 15000 miles? I had to hit 25000 before they accepted me! Perhaps it's because I travel on the low fares a lot