Read extensively. The university library's an amazing resource. Yours might come with access to online research libraries, too. Combine that with Internet resources such as Wikipedia, blogs, and so on. Speed-reading can help you browse through information quickly so that you can focus on the good stuff.
Write. Writing is a great way to remember what you're learning and reflect on how you're doing things. This will help you get better and better at what you do, and you'll be able to recognize the things you're good at and that you enjoy. If you write on a blog, you can use it to reach out to people. Write about what you're learning, and you'll help other people who are learning about it too. Write about what you're doing well, and you'll start building a network and a reputation that will come in really handy when you're looking for work.
Connect. Find out if there's a Facebook group for your incoming university class. If not, start one and invite other people to join. It's a great way to connect with people even before the first day of class. Feeling shy? That's okay, everyone is too. If you focus on helping other people connect and make friends, you'll become more and more comfortable, and you'll make friends along the way too. Don't hesitate to look for role models online, too. Many people have blogs that you can read to get a sense of what life is like in their industry. Read, then comment, then contact them, and you'll get a head start on growing your network.
Behave online and offline. The Internet remembers, and even sites that promise you privacy occasionally mess up and expose things you've shared to the world. Think twice about posting pictures of wild parties, underwear-on-your-head shenanigans, and other things things that future employers and coworkers might take against you. In fact, since just about anyone can take a picture of you and post it up on the Net where you don't have control of it, you might want to keep clean entirely. You don't need to posture to be cool, and you can have fun without doing things you'll regret.
Don't let yourself be limited by anything or anywhere. I took my bachelor's degree in a university in the Philippines. Great school, but it didn't have all the courses I wanted. =) I was on the Internet learning from course materials from everywhere: MIT, Georgia Tech, wherever I could find information. Now there are even more choices. Check out places like MIT OpenCourseware and Stanford iTunes for free courses. This is great not only for learning things, but also for getting a better sense of what you like. In fact, it might be a good idea to check the courses out now before you declare a major. You don't need to understand everything. You just have to get a sense of whether you'll like the course or not. That way, you'll spend less time switching around to find something you enjoy and will use.
I think I'll make a few sketches about this over the long weekend. =) Any other tips for incoming college and university students?