I hear you. I have four hundred fic memories (because I don't differentiate amongst fic/ficlets/drabbles) and that is probably overwhelming.

The posting thing is easy. You log into the sockpuppet account they told you about in your assignment email (they give you the password) and post the story with the header they posted on the comm. Then you tag accordingly. If you want, check out past posts to see how they're done.