I had an opportunity to be a reviewer of a new book about Firebug written by Chandan Luthra. This is actually the second book dedicated to Firebug and so, you might also be interested in the first one.
The book is labeled Instant Firebug Starter
Monitor, edit, and debug any web page in real time with this handy practical guide.
Instant Firebug Starter is a practical, hands-on guide that provides you with a number of clear step-by-step exercises to help you take advantage of the full power that Firebug offers. This book will give you a great grounding in using Firebug to debug, fix, and optimize your web pages.
The book starts with an introduction to the Firebug world, explaining what the tool is for and continues with a description how to successfully install Firebug into your browser. All you need to know if you want to get started with Firebug and tune your web site to perfection.
The next part of the book explains basics of Firebug user interface and gives you an overview of all the panels in Firebug. This is great even for those who have basic understanding of web development and Firebug.
The last part of the book is the most interesting and I believe useful even for advanced web developers and Firebug users. It covers top 17 features you'll want to know about. This is great place to learn some tips & tricks about HTML inspection, editing as well as AJAX debugging or page load performance monitoring.
If you are just starting out with web development and looking to improve your site with Firebug, then this guide is for you. If you have a basic understanding of web development then this guide is easy to follow and will benefit your site no end.
If it sounds interesting, just go ahead and learn new stuff !