Much of Fantasyland and Tomorrowland are open during MM. I copied this from AllEars:
"Magic Morning is generally offered every Sunday, Tuesday, Thursday, and Saturday. It allows guests to enter Fantasyland and Tomorrowland one hour before park opening. The following attractions are usually available (subject to change without notice):
Alice in Wonderland
Buzz Lightyear Astro Blasters
Dumbo the Flying Elephant
Finding Nemo Submarine Voyage
King Arthur Carrousel
Mad Tea Party
Matterhorn Bobsleds
Mr. Toad's Wild Ride
Monorail
Peter Pan's Flight
Pinocchio's Daring Journey
Snow White's Scary Adventures
Space Mountain
Star Tours"
The rest of the "lands" open at regular park opening, except for ToonTown which opens an hour after regular park opening.
As far as touring advice, don't do Nemo during MM - it eats up too much time. Most people like to hit the dark rides (mainly Peter Pan) since that line can get much longer once the park opens. Space Mountain and Star Tours both have FastPass during regular park hours, so it's not as important to hit those during MM either.
