DarkRoast, I am glad you are enjoying your 650! When you download calibre, it also comes with a short user guide. Although I also recommend the tutorials on the calibre website that Latinandgreek pointed you too. There is a whole section of MobileRead dedicated to discussing calibre. If you have any questions, then it is a good place to seek help.
https://www.mobileread.com/forums/forumdisplay.php?f=166
Geographic restrictions are complicated and frustrating! Especially when you can buy the same book in paper but not digital. Here's a good article which explains more.
http://ebookreadersresource.com/eboo...c-restriction/