We use an email list to actually send and receive submissions (so that people's work isn't posted publicly), though yes, the feedback threads are posted here. There are particular formatting guidelines and a weekly submission schedule, so you can't just post whenever you feel like it. There are no genre restrictions, but we're mostly geared towards speculative fiction writers.
We'll have the rules and everything up soon--probably this weekend--as soon as we can import that stuff over from the TWG database.