If I were to join facebook?

[Spanky]

will it tap into my mailbox and send "friend" message to my connections? As a writer, can I use it to give people free downloads? or direct people to links for my books? Or put up blurbs from my books? Or what else?

[Y]

You can make a promotion page for your writing. There's an option for that and a great way to market.

Basically, people like your page, and they get your posts in their News Feed. And yes, you are able to do all the things you listed, as well as post pictures and create Events (for Author signings, readings, etc) so people can know where you'll be for something.

[Mohammad]

Yes you can, and additional more features.