Here is my low down on the dorm life:
It all depends on the school and which dorm you get put in.
At my school (california polytechnic state university), we have many dorms that are kick ass. The RA's are chill and laid back, and know that partying takes place and just turn their heads.
However, the dorm I was put in sucked ass. My RA's were fucking NAZI's and would go around looking and searching for any illigal aftivity which was taking place. Most of the people in my dorm never drank or partied. Those that did got kicked out for lame reasons. I myself also got kicked out late in the second quarter.
Compared to dorm life, living on my own in a house is turning out to be great (except for getting stuck with annoying, stupid, inconsiderate, shitty roomates (happens alot so get used to it)
If you are going to a private school you will have a much better chance of having wet dorms (which means you can drink alcohol). State schools usually have dry dorms so you will have to be careful.
I have come to believe that any school will have it's share of good dorms and bad ones. My suggestion is that within the first few weeks, make a decision of whether or not you are in a party dorm or a strick dorm. If within the first month, most of the people are not going out and excited to party, then you are in the wrong place (assuming you do). Switch dorms as soon as possibly. Ask around to find out which dorms have the people who party. Most often the dorms with the residents who party the most, will have the RA's who let it slide the most.
I wish I had swtiched dorms, it would have saved me from getting the boot. Just learn from my mistakes and don't follow my footsteps. Party on tho!!!