ITC 2013 Registration will open in the summer of 2013.
Until then, here are some links to let you reserve your hotel room.
You can book your room now, and purchase discounted tickets to Disneyland and California Adventure starting July 3, 2013.
Getting to Disneyland and ITC
Here is the link for the SuperShuttle, the easiest way to get from the airport to ITC. Save on parking, save on rental cars, and who would want to leave the Magic Kingdom anyway?
The Disneyland Express
Or, you use this coupon for your discounted ride on The Disneyland Express from the airports. No reservations required. See the coupon for boarding details.