Anyway, once you're done revising, and for the best quality work you'll be doing this a lot, then you can post it. To do this, simply click on the new thread button, choose a prefix and a title, and copy and paste the fic from a word processing program. Now here're some important warnings. Do not format the body of the text with vibrant colours and or decorative fonts, do not change the text size, and do not align the text to the middle or right --always left-align. This makes your fic readable and doesn't make your readers want to gouge their eyes out. Next, and this is another important bit, double space your lines. For some reason, Vbulletin forums don't understand the concept of pressing the enter key once, and so normal text from a word processor often lose their line breaks.
Finally, click post and wait for a review. The F&W is a bit dead in terms of reviews at the moment (because of the contest), but it'll liven up in a while, hopefully.
Hope this helps and don't be nervous. We're here to help. =)
EDIT: Damnit, Marcin. xD Ninja'd.