The full text of an upcoming O'reilly book on generics and collections in Java 5 is available over at java.net as a PDF. The author would like feedback. While the book certainly covers more material that what's required for certification, it looks like a great resource.
Here is the blurb from the site:
Title: Generics and Collections in Java 5 Authors: Maurice Naftalin and Philip Wadler Publisher: O'Reilly Media, Inc.
Phil Wadler and Maurice Naftalin are writing a book titled "Java Generics and Collections", to be published by O'Reilly Media, Inc. This project is for the book's technical review. We are posting draft chapters to the group, for download and comment by group members. All members of the Java community are encouraged to join and comment.
All group members should subscribe to the mailing list email@example.com. We'd like you to post your comments to this mailing list. We would like this to become a discussion, so don't hesitate to respond to other reviewers' comments. However, if you prefer, you can send your comments directly to the authors.