Robert R wrote:
Good idea. Go to canonusa.com, all of Canon's lenses are listed along with reviews. That is a good place to start. You could also go the B&W's website, they will also have Canon lenses plus lenses from other manufacturers, plus customer reviews. There is a lot to be learned just from reading the reviews. There are many good lenses out there, be sure you order the one with canon mount.
I like photozone.de for reviews. They have technical reviews along with user reviews. The user reviews are not as precise obviously.