Age isn't everything. Trust me, I'm 17 (almost 18) and people are often surprised to hear that--they think I'm 25.
This site has been the best thing my writing has ever seen. I also printed A LOT of tips from published Christian authors from christianbook.com (you go to the fiction section and somewhere in there there's a list of great articles, or at least there was, a year ago, no guarantees now).
I bet there's at least a few teens who write better than adults, not that there's any reason for us to get cocky, but hey, if a person actually manages to finish a manuscript, who cares whether they're 10, 14, 25, 50 or 80?
Oh, and I almost got caught up into the PublishAmerica scam. I submitted my first manuscript to them (thinking they were legit), and they were going to 'buy' it (whatever that means in their case). Fortunately, I had a funny feeling about the whole idea, and turned down their offer before they mailed me a contract.
The good thing about that, (besides the fact I'm not stuck in a contract with a bunch of scammers) is that I did a complete overhaul on my novel last year. I had thought it was finished, and opened it up to do some basic fine-tuning (check my punctuation, etc), so I could submit it elsewhere and discovered that it was actually a bunch of crap. My sentences were choppy, and my sub-plots were, well, boring. I smoothed it out, replaced most of the sub-plots, added others, tightened the main plot, and am now very happy with this novel.
...Now I'm working on improving the narrative in my short stories. Everyone who reads them says I use too much dialogue. I guess that's because I feel the story has to be short, and neglect to 'tell the story' so to speak. My short stories usually read like scripts.
Good luck, PM me if you ever want to talk about writing with someone close(er) to your age.
Kacy