Books/series should be relatively clean in content - no erotica or covers with not fully dressed characters. Adult romance is okay.
You run the post and giveaway on your site and send me the permalink/link to add to the read-a-thon schedule. Posts must be up on your scheduled date by 12 am EDT and you must allow read-a-thon participants one extra entry. Other entries (following your blog, following on Twitter, etc.) are up to your discretion. My only advice would be to not have the required entry be to sign up for your newsletter or follow by email, as that may turn away bloggers, so I would add that as an extra entry.