Honestly, this was a real point of contention for me.
The local colleges don't have librarians telling studnets to be quiet, so it turns into a "hang out" area. I soon got tired of telling people to be quiet.
The local library was losing money, so they have "events" to get children to read books (i.e. Dr. Seuss day). This basically makes them de facto day-care centers. I couldn't believe how many screaming kids were running around, with no one telling them to be quiet!
Finally, I found the Kaplan study center, which I was eligible to use since I had taken their Live Lecture series for Step 1. I love it. It's quiet, professional, and there are plenty of others there going through the same hell I'm suffering through! That's very important for your morale. At least it was to mine!