One of the perks of being in sales is autonomy. If I've had a particulary good week, I'll treat myself to some time loitering around Barnes & Noble. Inevitably, a Disney guide book or two end up in my stack. In fact, I found about this site reading Rita Aero's book. I also highly recommend the Unofficial Guides.
That reminds me of a funny story. I always used to kid DD about 'that guy in the Mickey costume.' She firmly held to the belief that the characters are real until she was nine. I hope I haven't shattered any adult's fantasies here. I picked up my first guide book about the time she was six, and was talking about it one night over dinner. She piped up and asked, "Does it say anything about Mickey being real?" Of course I tap danced and said yes.
Our ritual seems similar to others in this thread. We'll always watch the vacation DVD before going (in fact, it's about time to do that!). We almost always watch 'A Goofy Movie' before we leave, too. It's a road trip movie we've had in the library since DD was very little. Now she's ten, and it's still part of the tradition.
About 30-60 days out, I'll count down the days on our paper calendar. Every morning over breakfast I'll announce how many days we have left and we'll talk about the things we'll do.