Express is available on all attractions except for the street shows, playgrounds, and Woody Woodpecker's Nuthouse Coaster. Mummy should have express available when it opens, but you never know, I assume it will.
Anyway, here's what I've found to be the easiest way to tour the park. This is a new version where I've added Mummy. I haven't been able to test this plan, but its fairly close to my original plan which works great.
Get to the gate at around 8:30 (when park opens at 9). Gates usually open at 8:45. As soon as the Gates open go to Mummy. Hit Mummy first thing in the morning. After Mummy, head back to the front of the park. If Shrek is 15 minutes or less, see it. If 30 minutes or more, obtain an express pass. After Shrek or after obtaining a pass, ride Jimmy Neutron.
Next, walk through Hollywood into Kidzone. Ride E.T. After E.T. head into World Expo and ride Back to the Future if you must.
Now is the time to hit Men in Black. It seems kind of late to hit a super headliner like MIB, but it usually takes 2-3 hours before it gets busy.
After MIB, ride Jaws and after Jaws, hit Earthquake.
At this point, the only things left are Twister, T2:3D , and all the shows (and playgrounds of course) Hit these at your leisure. Save Twister for later, as the wait usually decreases as the day goes bon.