Yep congrats! Here some advice from a profs point of view:
1) Make the most of your time there - be open to ideas and also not afraid to debate ideas and concepts with your profs. As long as you are respectful and evidence based in your approach, you will win their respect. One of the great things about academia is that it cherishes ideas and creativity. Try to learn concepts not just facts.
2) During your first year there try to engage with some of the senior students in your program. There are usually a number of clubs and societies for each of the major faculties. When talking with these students, get the scoop on what the best classes are and which profs are movers and shakers versus which profs are deadwood (unfortunately every school seems to have a few of the latter). You don't or may not be able to completely avoid certain classes, but consider who is teaching in relation to your subject. Sometimes students get turned off from a entire field because of a bad prof. Try not to let this happen to you. If a subject really interests you, dig a little deeper then the course content and supplied text and do a little self teaching. Ask senior students or other profs for guidance here. Part of the university experience is to turn you into a self learner by the end of your degree.
(aside - want to know if your prof. is really a crackerjack or well suited to the course - look up their publication record. Have they published recently - how many papers in this and the previous year?)
3) Related to #2. Make a real effort to develop social relationships with people in your school, faculty and program. This is easier if you are moving away to a new town for school and are forced into making new friends. Its always a shame when I get hometowners in my courses who make little effort to integrate themselves into the culture of their university. I don't think you can get the full experience of an undergrad by maintaining what is essentially your highschool lifestyle when you go back home. I'm also pretty sure that I learned as much, if not more over beers and coffee then I ever did in a lecture hall.
4) For the courses/profs you like best, make sure you make at least 1 appointment with them during the semester to talk about the course content or even just to talk about the field in general. This serves a couple of purposes. First, you could benefit from the one on one interaction. Second, the prof will get to know you as someone who is sincere and engaged in the course. Here is a little tip if you need an ice-breaker. Go to the profs website and download one of their recent papers. Ask him/her a couple of questions about it. Yes - this is a little ego tripping, but it really works. I did the same thing when I was engaged in my academic interviews!
5) Ask questions during lecture regularly. Try to raise a question or make a comment in a given class at least once a week. Again this will get you noticed by the prof. It will also identify you as an engaged student by other students in the class. Being a 'doer' means you will likely find good partners in labs and other group excercises. Also, be on the alert for other 'doers'. Talk to them outside of class, go get coffee, form a study group, drink a few beers (for you maybe in 3rd year
).
6) University culture is changing and there are lots of great internet resources. Often the course website has a discussion board that is sometimes moderated by the prof or a TA. Use the chat board to post questions and read it regularly. The discussion board is often a great study group tool.
7) Consider the possibility of getting a part time job with a prof in his/her laboratory for the summer or during the semester. While these positions don't often pay especially great, you often get teamed up with graduate students who can be great mentors. You can get engaged in research and be getting paid for work that is directly related to your studies. Sometimes it is harder to get such a position in your first year. Again, getting recognized by profs is helpful here.
8) You will be bombarded with the 'grades are everything mindset'. Good grades are great, but they don't mean everything. Always remember that your education is really about you and your learning - it isn't about where you stand relative to the class average. Personally I really like the engaged students and would rather have a solid working, well organized B-student working for me in my lab than a genius but lazy A+ student. Most profs can see through shallow grade-sniffers.
Hope this doesn't all sound too preachy (I realize it probably does). I think my undergrad was one of the better 4 years of my life - maybe a little less fun than graduate school. I wish you the same enjoyment that I had!!!
Best of luck!
Ok, ok, so maybe that was just me, but you get the point! 
