You can buy the Gleim Commercial study book, study everything in it on your own and at your own pace, then find an instructor to endorse your logbook when you are ready to take the test. Most FBO's have testing centers and I think most of them use LaserGrade software to do it.
Here is a list of testing centers from the FAA.
http://www.faa.gov/education_researc...st_centers.pdf