Figured this would be a good place to mention it, because Warren Ellis has made it plain that fiction should not be posted here. Please don't sic the arse eels on me for blatantly advertising my new website. The arse eels and I were close once, in the summer of '76, so close it hurt when embraces became parting, pulling apart, oh, arse eels, how you wept--how I wept--how I weep even now. I'm fine fabric come undone without your slimy touch.
Anyway. Quill-thrill is free and in beta. We've got some courses on basic writing and critiquing pieced together from a variety of sources (OWL, various undergrad and grad courses, Will Burnett's books, etc.), and it's a great place to post and critique fiction.
You might want to check out www.youdothatvoodoo.com too, for my adventures in screenwriting, and a bunch of sample scripts covered by a Creative Commons licence.
We have a pretty cool site. No arse eels. That's Warren's gig. We do have- what's a hip Internet lure? Unicorns. We have so many unicorns. SPACE unicorns.
And we are so pleasant to be around. Look how pleasant I am. LOOK!
Just to play devil's advocte... what makes this site any different from any of the trillion other 'post your fiction, have others critique it' sites? They are a dime a dozen and critiques always end up being amatuerish.
That's just my two yen. I hope your site does well.