I don't know of any sites that shows the details of how to rehair a bow. However, there are two very reasonably priced books available on the subject. The books are the
Violin Maker's Notebook by Henry Stobel, and
Violin Bow Rehairing and Repair by the late Harry Wake. The Wake book is somewhat dated, but quite adequate for the beginner.
However, don't expect to read any book and become an instant bow rehairing expert. When I was first learning the art, my mentor told me that I would get the hang of it after I had finished my first hundred or so bow rehairs (and breaking two or three while in the learning process). It turned out my mentor's assessment was quite accurate.
