Boston University's main campus runs for about 1.5 miles along Boston's Commonwealth Avenue, from Babcock Street to Kenmore Square, then down Beacon Street to Massachusetts Avenue. It is bordered on the north by the Charles River and the Esplanade, and by Storrow Drive. It is bordered on the south by the Massachusetts Turnpike (I-90), except for a small area called South Campus.
At the east end of campus lies Boston's historic Fenway Park. Numerous clubs and bars abound in the streets surrounding Fenway (such as Lansdowne Street), making for an interesting night life right near campus. For fun further from campus, downtown Boston holds a vast wealth of entertainment. Of course, the T is always an option for those not brave enough to drive into downtown Boston on a Friday night. However, the T shuts down around 12:30am for most lines, leaving barhoppers stuck paying outrageous amounts for a taxi.
There are 8 T Stops, all along the "B" branch of the Green Line. Taking the T in the outbound direction above ground (any stop after Kenmore) is free. This creates a tight squeeze on the T for students and commuters alike.
There are 7 major residence halls on campus. This does not prevent a huge housing crunch at the beginning of each academic year, when students are sometimes temporarily housed in a hotel across the Charles in Cambridge, and provided shuttle buses to the main campus until they are found permanent housing.
Some hints for the new student coming to Boston University, from someone who has been through it:
With 30,000 students, anyone starting their freshman year at BU should expect their core classes to be taught in lecture halls with hundreds of their fellow students. As classes advance, classes naturally become smaller. Some (like me) find the huge classes to be too large to really understand the material. Use office hours generously! That's what they are there for.
The dining halls are actually not as bad as people say. Of course, avoid anything you can't readily identify. However, most dining halls have a baked potato bar, and a pasta bar, along with a salad bar and soft serve ice cream machine, so chances are you'll find something edible.
West Campus is a bitch of a place to live. You have to leave 15 minutes before class and walk about a mile in the early morning cold to get to your classes (depending on where your classes are, of course). If you are relegated to West Campus, either get a T pass ($35/month), or learn the shuttle bus schedule... or learn to get up early and enjoy your morning jog to class. You WILL get pissed at everyone who lives in Warren Towers, The Towers, and Shelton Hall when they tell you they wake up 5 minutes before class and go to class in their pajamas. However, there is one bonus: West Campus is right where all the sports are, so if you're an athlete, or just like watching them, this is the dorm you'll most likely want to live in.
The Towers is the closest hall to the science labs, Warren Towers is closest to the liberal arts and engineering classes, and the arts and general studies classes are halfway in between West Campus and Warren Towers.
There are three CVS's on or around campus, lots of restaurants (including the Student Union, which has a Burger King, Cranberry Farms, Ben and Jerry's, etc.), and a few Campus Convenience stores. If you can, avoid Campus Convenience (we used to call them "Campus Conspiracy"). They are WAY more expensive than CVS, but you can use your points there if you are broke.
Most of all: Don't be a homebody! Make the most out of living in one of the largest universities in the US, which also happens to be in one of the best cities in the country. Explore! Have fun! But stay off the Esplanade at night.