I use the KRK Rockit 5 monitors, and for the money I don't think you can beat them. They sound great and are very inexpensive. They have many different models and it is all about finding what is best for you. I would recommend these as they are not too big and loud, but also give you enough headroom to get what you need out of a good recording. Here is a link to Guitar Center's page where you can read about them.

http://www.guitarcenter.com/KRK-Rokit-Powered-5-Generation-2-104908710-i1403132.gc