1) work hard - start to study at least three days before a major exam, a week for an exam that you absolutely have to do well in, aim for 90/100, "A"s, and/or HP, don't just settle to pass
2) play hard - try things that you haven't tried yet, give it a shot! you're in dental school already, you're here...have fun! If you don't drink, try a glass of wine, ask a person out on a date, talk to a classmate that you haven't said hi yet, heck, say "hi" to someone that you walk pass by, do something that has nothing to do with school
3) hang out with classmates - dont' just do to school be all quite and then go home in your little shell. Meet classmates, find out where they're from, their name, their hobbies....your best man, maid of honor, and/or your wife/husband may just be one of them
4) talk to professors - get to know them, go to office hours, ask questions outside of class, you'll be amazed how much this interaction will benefit you. Once they know you by first name bases, you'll get all the attention you'll need
5) get involved - join organizations and/or clubs, meet more people, start to build you C.V.
6) Study groups - you'll be amazed how effective this studying method is. Try to limit yourselves to only 3 or 4 to be effective. When it gets to large, it turns into a social gathering and end up talking about everything but the subject you're studying
7) Go to sim lab on after school hours - only if needed or desired. First year, only waxing take up most of your time.
8) Reach out - volunteer, shadow, contact program directors for the specialization that you may be interested in. Build a relationship with those program directors, inform them of your academic progress. It's never too early to plan if you KNOW what path you want to walk on (if you want to specialize).
9) SDN - maintain your contribution on this site, people need ya! We helped you, you got the info that you wanted, now give back, stick around!
10) Work out - stay in shape, join a club, run, start to do cardio, work on your lower back (hyperextensions). Save your back and get it stronger. There's no point for you to get all "A"s and then you're not going to be around in another 20 years. Get more energy inside of ya!