During my recent foray to Europe I had the pleasure of meeting Mr. Reinhard Hopp, a man with a keen appreciation for the Honda CB-750 in particular and Honda inline fours in general.
Mr. Hopp's passion for the CBs ran so deeply that he wound up devoting some 5 years of his life to researching and writing what is arguably one of the most definitive books on the subject:
http://www.honda-cb.de/en/index.htm
As well as a follow on book on later models. In addition, his website is available in both English and German, and in my opinion well worth a look if you have an interest in these bikes as I do:
http://www.honda-cb.de/en/index.htm