I think it depends on what you want from the book. Growing squash is fairly straightforward so a whole book devoted to step by step techniques may get a bit boring?
I liked the compleat squash book - because it has a small amount on growing echniques (and I mean small) and lots on the different varieties, which ones taste good or are just better for decoration etc. Having tried a fair few varieties now I have found the recommendations to be worthwhile. Also the photography is beautiful. But it is a bit more of a coffee table book than a growing techniques guide.
I also was given Amy Goldmans Heirloom Tomatoes for Christmas which I love for exactly the same reason.
Hope this helps a bit