Have you tried visiting your Friendly Local Game Store? They will probably be carrying Seven Worlds books or can order them for you if they don't.
Want to purchase printed books or book/PDF bundles? Head to the Studio2Publishing website to get printed versions of the Setting Guide and the Campaign Book, as well as Book+PDF bundles at awesome prices!
Just want to get PDFs? You can visit the Studio2Publishing site as well, or head to DriveThruRPG and RPGNow to get our full line of PDF products!