It doesn't matter if it's fiction or non-fiction. It's good to write. I can't write stories about me, I've tried a hundred times. So I break off pieces of myself or pieces I wish I could be, and I put them into my characters. It gives them their soul.
If you ever want some hardcore feedback (and I mean hardcore, don't ever go there if you can't take critisism,) a good place to post your work is authonomy.com. It's run by the publishing house: Harper Collins. I used to try to post Angel in Black there, I am going to do it again, once I get it closer to "done" and edited really well, because some of the people on there are brutal. You need 10,000 words to go live and every month they vote for books to be published for real. It's a good goal.