I did Summer@Brown last year and it was an absolutely amazing experience. Honestly, it isn't that hard to get into as long as you have decent grades. I stayed on the campus for 4 weeks because I took a Creative Writing course. The dorm I stayed in was called Perkins, and it is known to be the farthest/worst/smelliest dorm building on campus, but it was actually alright. The other dorms are nicer and closer to classes.
Making friends is very easy at this program. The RAs are wonderful and you all get to know one another on the first day. There's also an ice cream social where everyone in the program well...eats ice cream together! I thought I was going to have a very hard time transitioning to college life, but everything went smoothly.
The course load varies per class. In my class, creative writing, we read an entire textbook and wrote a lot of different assignments, as well as a 10+ page final! Honestly it didn't take up all of my time though. I still had time to socialize.
The trips on the weekends are awesome. They are optional and you have to sign up. I went to Newport and Boston and they were both free, except for what you have to pay for when you do go there. Honestly, I only spent my money on food and a little shopping here and there. It wasn't too bad.
@unicornrainbow- Yes that does mean you put down a teacher. I think they email your teacher or something, but I can't be too sure. My memory is fuzzy!
If you have any other questions don't hesitate to ask me!