How to kick off viral marketing

I'm thinking about offering a free ebook on my site (webmastershelpguide.com) to get some good traffic, and I was thinking how do I start the viral train off?

Should I find a viral script that makes you have to email someone for the ebook or just give the ebook away like that.

How should I premote my free offer, I will through twitter and facebook any other ways I should (social bookmarking if so what sites are best any automation way)

Hopefully this thread will help other people too!

You can offer your ebook an incentive to visitors for referring other visitors. So for example, you can say "To download this FREE ebook, please refer 10 visitors to this site."