Historical Bigfoot, by Chad Arment, is on my list. I've read a few reviews of the book over on Amazon.com (by the way, check out my own reviews and Listomanias!) and it seems interesting, and a good resource. I don't believe the book delves into theories or attempts to solve anything, just a record of news clippings from the 1800s to about 1940.
Since I've ordered Captured! (Stanton Friedman's and Kathleen Marden's book on Barney and Betty Hill) the other day, I have to wait on this one.