7 if you count the ukulele and archtop books
Irvine Sloan - Steel String Guitar Construction (the one Violet is reading)
Very old school, all done with handtools. A great book for its age. Doesn't give you all the info
Cupiano & Natelson - Guitar Making: Tradition and Technology
I don't like this one at all. Its very detailed right down to step by step instructions for each task. its a good reference book but not a good read
Jonathan Kinkead - Build Your Own Acoustic Guitar
This has the best pictures by far. its a really vibrant book and really a good update on the Sloan one
Melvyn Hisc--k - Make Your Own Acoustic Guitar
This combines the best of all of them. good colour photography, enough info to get you going and easy to read
Jim Williams - A Guitar Makers Manual
This is another old school one and I don't like it at all.