Some tips:

• There is a brochure with a map in a display near the entrance which also shows rest areas and bathrooms. I'm pretty sure there's more than one bathroom as there's a lot of nooks and crannies. I wandered past at least two bathrooms. There's a rest area with seating and vending machines, too.
• If you go early but aren't in the first few groups to enter, go up to the second floor while it isn't so crowded then back down since the congestion won't be much worse than when you entered
• There are lockers and lockable chains at the entrance area for bags, strollers, and luggage
• Ladies - there are exhibits with mirrored floors and some long dark wrap skirts outside those exhibits if you need them
• The "Light Shell and Light Vortex" room which resembles being inside a strobe light show gets very warm and can be a bit disorienting

Crowds: The lamp room probably had the longest wait while I was there. The digital waterfall also had people setting up camp at the top and no staff to enforce a time limit, so good luck there.