You'll get an 18 digit code from Digital River. Check your spam box in case it went there. Enter it into the preorder site and it'll direct you to another page where you'll receive your 20 digit code and a link to enter your 20 digit code into another site. There's various threads with links to where you'll enter your code. If you happen to get an error when entering the 18 digit code, refresh the page and try again.
Star Swirl on Behemoth AKA Best-hemoth AKA The Cool Kid's Table----60AST, 60WHM, 60SCH/SMN, 60BLM, 60MNK, 38 PLD, 34DRG, 31NIN, 27MRD
FFXI- Derpypony on Asura
Check out the Dream Network, a Twitch.tv community for XIV fans, featuring notable streamers like Mr. Happy, MTQcapture, Rahhzay, and Slyakagreyfox! http://dreamnetwork.tv/forum/index.php
Then maybe check out myself, EquestriaGuy, on twitch at http://www.twitch.tv/equestriaguy