This is a good book, I like the format of "howtos", i like the way it concentrates particularly on the audit trails sections (note the audit in the title refers to audit trail rather than security auditing) on the functionallity available from Oracle. This is important as still most sites I visit do not employ audit trails in the database itself. Often sites use auditing in the database but for application level activities. It is important that sites audit database activity with the same vigour as application level auditing and understanding whats available with the database is a good start to set up and run and use something.
The book is focused at a hardening level and covers various privilege and access issues. It also covers encryption and authentication and of course auditing solutions. It also covers the new technologies/products from Oracle; Audit vault and Database vault.
This is a good book.