1. Get an editor. No fanfic will be posted without going through one. I do not provide the editing capabilities of the Archive. I always encourage those wanting to post to the Nfic Archive to first go through the PG site, the PG Lois and Clark Fanfiction Archive, where you will be assigned to a general editor before they post your fanfic. It is helpful, of course, to have a PG version of your nfic, since they only accept fanfic with ratings of PG-13 and under.
Another good place to start is the Fanfic Message Boards. This also is a good place for immediate feedback.
There also are a number of FoLCs who might be willing to edit for you (if the time permits for them, so please write to ask first ;).)
2. Grammar ... grammar ... grammar! Using MS Word's grammar check is not sufficient. Bill is a programmer not a writer. ;) Also be wary of the spell checker, although it is good to use before submitting to your editor (so you don't drive them crazy) a spell check may also miss word fragments.
Please check out the Fanfic Archive's Grammar FAQs
3. I reserve the right to refuse any submission.
4. Submission email address. Must be submitted as a text attachment to stories @ annesplace.net