1)
Get the idea of doing out of your mind immediately. You can't, it's a fact, just get over it now. Pick a few things that are "must dos" and focus on them. Take the time to appreciate your surroundings, because the only time I can tolerate someone stopping dead in the middle of a walkway is someone looking around for the first time in awe going "omg...I'm in Disneyworld!"
2)
Do your research. Look at menus, ride descriptions, crowd expectations, show times, ride refurbs and closures, etc. If you wouldn't go to Zimbabwe with no idea what's there, you shouldn't go to Disney with no idea what's there. This will save you from sitting down in a restaurant only to realize you don't actually want anything they serve, or getting in line for a ride that at the end you realize isn't really your thing. There's a wealth of information out there and it's not hard to access, therefore there's no reason to get into parks and get angry because you thought Big Thunder Mountain was a peaceful train ride.
3)
Never expect to be on time EVER if you're using Disney transportation. I love Disney transportation. I love knowing that I have a way to get around without having to spend extra money. That being said, I know that there's "quirks" to using Disney transportation. Give yourself more time than you think you'll need to get places, particularly if you're trying to get to an ADR or anywhere you need to be at a certain time. Better to be early and have the opportunity to explore a little rather than being late, getting mad and rushing around.
4)
Disney is not like lounging on the beach with your ipod and a book, it's work. Expect to leave the parks sore and tired. Expect to relish flopping into bed at night. Expect to love every minute of it. I consider Disney relaxing because it's not my normal routine and I love it there, but I know I'm going to be walking several miles a day and since it's NOT my normal routine, my body will react differently. Bring good (and more than one pair) shoes and make sure they're broken in, and comfy clothes.
5)
Beware buyer's remorse. Disney is full of shiny new merchandise..and you will want it. Of course you'll wear that giant Goofy hat around the parks, but what will you do with it when you get home? Who wouldn't want a Mickey balloon, but what are you going to do with it at the end of the trip? That 5ft tall Stitch plush is so cute...but will it be so cute at the airport or sitting in the corner at home? ABSOLUTELY treat yourself, ABSOLUTELY spoil your kids a little, and OF COURSE not EVERYTHING needs to be practical. Maybe sipping out of your Grumpy coffee mug everyday will be a little bit more satisfying than having to dust off a certain Swedish Chef plush that lives on top of your bookcase

not that I know that from personal experiece or anything! Also learn to take advantage of what Disney offers for free or inexpensively. Getting the ice water from CS places, pressed pennies, free segway trial, collecting park maps and guides, exploring the resorts are all good examples.
> Sorry if I come across a little snippy in some of these, it's not meant to be.
