If you're going to WDW, you must see the opening show at Magic Kingdom. Arrive there about 10 minutes before opening. It's so darn uplifting and it sets the day off right.
Also, for your first time to Magic Kingdom, take it all in ----- on Main Street, it's so pretty and the first time impression will last forever in your memory. And then again, seeing the Cindy's castle for the very first time, just savor the moment and take it all in. Aaahhh.
I agree with the other post, SEE SPECTRA MAGIC, pure awesome.
Take the monorail to the Grand Floridian and walk inside and out. Aaahh, just beautiful. Perhaps you can have a character breakfast or dinner there.
Also, videotape the Pooh ride and Buzz lightyear ride.