Going to college in the 21st century without a laptop is difficult. Sure, you can get by without one, but at the end of the day, do you really want to rely on a computer in the library being available when you have a 12-page paper due in two hours? (Or have to go to the library anytime you want to check Facebook, for that matter?) The answer, simply, is no, and at Northwestern, things are no different. Of course, computers are available to all NU students who need them, as there many buildings equipped with computer labs spread throughout campus. The wireless runs pretty well for the most part, and dorm rooms come with a jack to hook your laptop up to the school's landline Internet, if need be.
Individual schools and programs may have different software requirements, so be prepared to shell out some extra cash, depending on your major. Some programs recommend certain brands of laptops, but ultimately, when it comes to the computer brand, go with what you're used to, whether that's a Mac or PC. Regardless, you'll most likely be spending some big bucks, but the good news is student discounts will ease the financial burden a great deal. As for printers, students are pretty divided about how useful it is to bring one. Honestly, though, unless you feel like running to the library every time you need to print something, you might as well bring your own if you can. You might think it's excessive at the moment, but there will come a time when you'll be happy to have your own (or regret not bringing one up). The one drawback is paying for ink and paper and dealing with people on your floor asking to use your printer. The IT staff on campus is pretty helpful and knows their stuff, so if you need support, you shouldn't be lacking. Ultimately, your having your own computer will save you a lot of hassle—at the very least, you won't have to worry about that creepy kid in the library staring at your Facebook over your shoulder.