I give Anghel Leonard's JSF 2.0 Cookbook ([...]) a qualified recommendation, but with a couple of caveats. Certainly he succeeds in providing JSF recipes that, taken as a whole, are worthwhile for the typical developer to know. But there are curious gaps and omissions. A discussion of the DateTime converter fails to mention the default to GMT, addressed in JSF 2.0 with a context parameter that allows the application to default to system time. To be fair, the new feature is discussed in the section on I18N and localization, but it should have been mentioned in the discussion surrounding conversion...and the implications are left entirely to the reader. An entire recipe is devoted to a new JSF 2.0 element that specifies a required input...unnecessary, since this has been available since JSF 1.0 as an attribute to JSF input tags.
That being said, nearly every JSF developer uses a subset of the features available in the framework. For that reason, a cookbook can help fill in the gaps of feature that are rarely (or never) used. From this book, I learned a number of things about unit testing and management of JSF applications in chapter 9 that I didn't know, as well as file upload and management in chapter 3. The chapter on Facelets should be valuable to anyone that hasn't used it in JSF 1.2.
Strengths: "how to" recipes, RichFaces, unit testing and management
Weaknesses: selecting alternative strategies, "best practice", limited to specific JSF addons