Isn't that a great link?! It's one of the best things Marriott has developed to help us, that's for sure, and we were all happy last year when they first came out with it. Hopefully next year they'll issue updated ones, because without it I always had to ask TUGgers the same way you did.
About making reservations at the 12-mos mark through your account - I learned here that it usually works better and faster than calling in, and it's worked very nicely the few times I've done it. Just make sure that you familiarize yourself before that morning with the various screens you'll see. You can sign in anytime and click through all the way to the calendar to get a good idea of what you'll see, and then that morning you can go partway through just before 9 so that you're one of the first in line.
BUT, this year (during this last week, actually) a few people are reporting that there have been problems and delays with online reservations. I guess I'd try to do both at the same time, call in AND go through the online process, just in case those problems continue. Good luck - it sure is nerve-wracking!