its definitely possible to have a social life, work, do whatever you like and still stay on top of everything. I've managed to do quite well this year, despite working a couple nights a week teaching mcats for kaplan, and being active in extracurriculuars, student gov't, ortho/surgery club, and i go out at least once or twice every week, and we're also always doing something athletic, playing bball, raquetbball, kicks 4 kids flagfootball tourney, peds 3 on 3 tourney, did the broadstreet 10mile run in philly, went to DO Day on the hill, soma convention, etc. its all about being efficient with your time and being efficient with your studying. i go to the gym before class every morning, go to almost every class, try to get what I can out of it, listen to classes on mp3, and just stay close by reviewing the notes regularly. the week before the block exams, buckle down even more. you just have to get into a good routine, and if you're good with your time, i don't think it really requires more than a couple hours a night, but you just have to be really focused.
i also try not to stress going into exams. a bunch of us try to get our stuff together ahead of time, and we relax the night before exams, we'll hit up a local bar, watch movies. people in our class think we're crazy for not staying up all night cramming, but if you got it down, it all comes down to confidence, knowing you know it, and giving yourself a chance on tests.
a lot of us have actually developed a culture of studying too. you'll see the same usual suspects at the library or local study hotspots, its comforting to have your colleagues around you. its almost like "social studying" its nice to have an instant social outlet, plus group studying often helps too, teaching stuff back to each other. i like learning by trying to explain things, but i also learn well by listening, plus one of your classmates might be able to explain a mnemonic or way to remember something that could be helpful to you. but again, you have to be careful and focused with your time, and get your stuff done at your own pace. just find a system that works for you, adapt it, its completely personal. some people just read the notes over and over, others make study guides, flash cars, rewrite things, etc. do whatever works for you.
having good friends helps too. while toasting with champagne the night before our micro final, last exam of first year, one of my buddies added "to med school, its not how you study, its how you buddy."