The trouble with self-publishing is getting a fan base. In my own case, I publish a magazine, write a column, publish stories in F&SF and Analog, and I still don't do nearly enough. Unless you've got a lot of friends on facebook, you're going to have trouble attracting attention. The competition is fierce.
I think your best bet is to go to http://www.duotrope.com/
A quick search for professional markets for 12,000 word alternate history only shows Grantsville Gazette, with Asimov's, F&SF, Tor.com, and Writers of the Future as secondary markets. If you don't have professional sales to your credit, Writers of the Future is your best bet.
If you don't care about being paid, there are a lot of markets. The problem is that you probably won't get more than a few dozen readers.