A little late for the SLE #1 group, but I'll share some thoughts if anyone is interested.
I used a backpacking backpack (internal frame) to carry my stuff. It fit everything, was comfortable, and seemed easier to manage than suitcases. Not sure about how easy it would be to bring on a plane with, but just a thought when you're marching that first day.
Most of the windows can open, and if you fit your towel between the two panes of the window over the opening, it blocks light at night while still letting cooler air in. Plus it ensures your towel is dry for the next time you shower.
Set an alarm for 5 minutes before your expected wakeup time. It helps to have a few extra minutes to breath and ensure you have everything you need for the day.
Be sure to talk to the professors personally while you're there, especially if they teach a major you wish to pursue. I met one then was able to call a few months later when I had other questions about the academy. They do remember you if you take time to introduce yourself and can offer valuable insight.
MidCakePa is exactly right. I still talk to many of my squadmates from SLE, and I regard the experience as the best of my summer. It is only as good of an experience as you make it. Good luck!