Location

upload new fanfic for a brand new story
add chapter to fanfic to add a chapter to an existing story

Both located in the "You" block i the right hand column.

Posting

Title: enter the title of your fic
Book outline: should default to <create new book>

Rating

Required.

G: general - anyone can read it provided they can read and understand it.
PG: parental guidance recommended for under 13s - may hint at adult themes and contain minor/"cartoon" violence
MA15+: mature audiences 15 and over - adult themes/situations but nothing too explicit, moderate violence, drug use/reference, stuff like that
R18+: you need permission to create/view these, and you get that by bugging one of the admins (Torama, Vinnie, Whipblade) who checks your age and lets you in (or not). This is for the graphic explicit and possibly scary stuff.

Themes: tick what themes are mostly covered in your fic. This will make it show up in all ticked categories. Keep in mind that good fics tend to cover a lot of themes, so if your fic is a drama with a bit of comedy, a bit of romance, a bit of angst, you'd probably just pick drama.

Cover/sequential art: if you're doing a comic or want your story to have a cover page, upload the page in question with this field

Fic page: if you want to upload the story/chapter from your computer

Body: you can use it for an author summary, a blurb, blat the story into it or leave it blank

Editing

Each page you have permission to edit (all of them if you're an editor/administrator, just yours if you're not) should have "View" and "Edit" tabs up the top. To change anything at all about your fic (including deleting it) click the "Edit" tab and perform the appropriate actions.

Reading

Click "fanfics" in the menu. Click a title. If you want, leave a comment and/or use the 5 stars to give it a rating out of 5.