Covers well what you want to know as a web-app developer,
This review is from: Apache Tomcat 7 (Paperback)
The book has deservedly received some flack for being full of grammar mistakes and code-typos to the point where one may wonder whatever happened to editorial at Apress. It just isn't ok for a book.
On top of that Apress' web-app for submitting errata on it's books ignored my submission when I tried. They really don't do much to help themselves here. So never fail to include the code in the book as a usual suspect when things aren't working.
That said, the grammar-mistakes aren't showstoppers and the read generally flows well. Typically it is a missing definite article and such and not directly incomprehensible sentences.
While the book isn't the definitive guide on Tomcat for sys-admins (and doesn't try to be), it covers to the point what you want to know about Tomcat as a Java web-app developer. I believe it's also the only book to describe how to embed Tomcat in your application which is something I didn't find on tomcat.apache.org.