These are information-only sites that appear reliable. A good site for general information with photos and easy explanations. Not terribly extensive but worth checking. This is a medical site and not necessarily designed for the layperson, but if you want to wade through medicalese, you might find some useful information here. The Athletic Training program at California State University at Chico provides this very well-done web site.
Coaches can learn valuable information about treating and preventing sports injuries.
Again, not to replace consultation and advice from a physician. This is an excellent site to go for information about sports injuries. There's usually a new feature on sports injuries every day, depending on which sport is in season. Check their archives for good information on sports injuries. Definitely a site to bookmark.