When staying someplace new, I always check out the member reviews at TripAdvisor. There are always one or two cranks of the "there was a smudge on my window and they wouldn't give me a full refund!" variety, but on the whole you get a great overview and idea of what to expect. Just go to:
I too check TripAdvisor on a regular basis if I want to find out more about a hotel I am going to, but they do not do any bookings. I also check out www.lastminute.com, or www.lastminute.fr. I have had quite a few good deal for hotels in Europe. For instance, I auctioned on e-bay 2 nights with breakfast, 1 dinner and a guided tour of Nuernberg at the 3-star hotel Duerer in Nuernberg for 83 Euros. One night with breakfast there usually sells for about 125 Euros. There is also a German e-bay site called www.cultuzz.com where you can find some good auction deals for hotels in Europe.