Above I delved a little bit into the issue of size here. Make no mistakes, this University is HUGE. I'll never know everybody in my grade, major, or even just on my street. But if you seek out people with similar interests as yours, there's no doubt you can MAKE the University feel small-school. This has been so true for me in the Residential College- where you live for your first two years, take classes, eat, do your laundry, go to plays, see indie bands perform in the basement cafe, and study in a library all located within one dorm: East Quad. Imagine rolling out of bed, putting on jeans, and stepping next door to use the bathroom, then going across the hall for class. It happened to me. Some days I'd never have to leave the dorm if I didn't want to. Often I ventured out just to break up cabin fever- specifically during those dark long winters. I also had a couple friends around other places on campus.
But it was really nice to be so comfy and have conveniences so near. And many of my closest friends came from the same setting. The "characters" of that group are unmistakable, some of the professors will change your life and others will confuse and frustrate you. I don't feel as close to my LS&A professors from the general college.
Even if the RC isn't your thing, like many of my friends, I truly believe any person can find a niche here because there are hundreds of organizations, teams, clubs, etc.
Some frequent student complaints: lack of parking. If you can get by without a car, do it. I do. SO many of my friends have received dozens of parking tickets. They're like $25-$45 depending on where you go, and that adds up quickly. If you're in a dorm you probably won't have a car anyway.
Another complaint: roommates. If you're in a dorm, you can get them changed. However, if you're on a lease somewhere, make sure you think about who you're living with, or be willing to live isolated. A whole year with somebody nasty can really drag by.
Food: meal plans are a rip-off in my opinion, but I think this differs depending on the person. I'm a vegetarian and did not find the best options available in dorms. On my own, it can be hard to get produce in winter months since I don't have a car. The buses will be your friend. So will your friends with cars.
North Campus: Chances are if you're an engineer or an art/music student, you'll be up on the island that is North Campus. It has its own feeling, separate from the main campus. If you choose to live on central, you'll have to commute 10-15 minutes to get to your classes. I rarely visit North but it is pretty and woodsy, and everything essential for survival exists up there as well (food, housing, study areas, etc.)
Where do I spend most of my time? If I'm studying, I prefer the "Ugli" aka the Undergraduate Library, the Fishbowl (computing site in Angell Hall), or the Union. To me, those places have the best computers and noise levels.
If I'm out partying I like the bars on Main St. as well as Ashley's and Leopold's. The bars on South University are really "sorority/frat" if you know what I mean. Not to knock them, just not my scene.
If I'm working out, I always use the Central Campus Recreation Building, or the CCRB. I go there because they have the most elliptical trainers, which are lower impact on your joints. There is usually a wait (irritating but worth it) for 5-10 minutes during peak hours.