There isn't anywhere that I know a hard and fast guidebook. The closest thing to a way to assess the value is to search how they fare on ebay the last ninety days or so. That isn't too helpful sometimes as the prices fetched can fluctuate from sale to sale for the same item over a few months!
One rule of thumb seems to be that of whether the material in the sets is available elsewhere on cd, the set is not as valuable as if it is not. The Clifford Brown material is all easy to find, and the Tina Brooks has been in and out (and one item is going back into) print for some years now. They will likely not command as high a price as others.
Here is a jazz board where Mosaics are often discussed, bought and sold, and valued: http://www.organissimo.org/forum/
There is even a separate forum there for "Mosaics and other Box Sets"!