So I wanted to advertise my book somewhere, but it's a work in progress, any sites relevant to that?

[Piratemom]

It's already public.

You advertise a book after it's published. Because you posted it to Facebook, you will probably not be able to interest a traditional publisher. So, you will need to self-publish.

Valid ways to promote a book including giving readings (local bookstores, libraries, high schools) passing out promotional materials, getting on radio shows or on TV (local station) posting to website like this one, attending events where people who read your writing will be and promoting there.