I use Trip advisor for every trip except Disney since there is better Disney information on this site and others.
Wherever new I am going I first go on Trip Advisor put in a search for the place I am going it then brings up lots of hotel listings and restaurants etc. I use those to get an overall sentiment of the place and sometimes good descriptions of the real rooms, not the ones they show in the pictures. People will even post pictures of the actual room they stayed in.
I then go to the left hand menu bar and click on Forums to see if there is a forum discussion on the area. These are very helpful and you can ask your own questions. I found out great information for my New York City trip and was able to make the most of my 4 days!