For books on using and understanding the Bluebook, search the Law Library catalog by keyword "bluebook".
***NOTE: some of these books are keyed to earlier editions of The Bluebook. Always double check that the rule cited in these materials matches the rule in the current edition of The Bluebook.
Maybe it sounds crazy that you'd need a manual to help you with a manual, but there are some, such as:
* This is a free citation guide that is not The Bluebook, however, most of its rules and examples are consistent with The Bluebook