WordPress

WordPress Bible by Aaron Brazell

Aaron Brazell has outdone himself with this comprehensive tome of WordPress awesomeness.
Great resource for working in WordPress.
The information and concepts in this book remains relevant. It's well written and easy to digest for an expert or layman alike.
This book helped me out a ton.
This is a good resource if you need to know, or look up, something in particular.
This book is probably one of the best books on using WordPress.

HIGHLY RECOMMENDED TO WORDPRESS USERS READY TO UNDERSTAND AND BUILD OR MODIFY WORDPRESS THEME AND PLUGINS.
This is a really good book.
Amazing book, goes in great depth on WordPress. Highly recommended for anyone really wanting to be or become a WordPress developer.
I loved this book. It is easy to understand and can also be used as a reference.
This is a great introduction to WordPress and customizing it.
Yes. This is a technical book. However, it has been helpful to me since I am so new to WordPress.

Digging into WordPress by Chris Coyier and Jeff Starr

There is so much information in this book it makes it a must have for anyone developing websites with WordPress.
The pages are beautifully done and extremely easy to read.
The code examples are precise and are all stuff you would use in a real world situation.

Professional WordPress Plugin Development by Brad Williams, Ozh Richard, Justin Tadlock, and Joost de Valk

If you want to develop plug-ins for either the community or commercial audience, everything you need to know is in here.
It's well written, honest, and comes from a collective background of collaboration and been-there-done-that experience.
This book is the perfect reference book.
It touches on all the topics you'll need to create a plugin for WordPress and it explains both the basics as well as the details in a very good way.
This has been the best book I have purchased on WordPress by far.
This is not a book on learning how to use WordPress, this book is for developers.
This book has so much useful information on working with WordPress that it will help anyone taking time to do custom work in WordPress.

Good book for beginners
Really good. Got started on my own while waiting on it. However. now that i have it I may re-do somethings. There is a lot here.
Good read. Teaches the basic in a clear way. Layout things out in process that explains how things go together.
The writing is light and friendly and easy to understand.
The book is excellent but you need some previous experience, not too much, but you cannot come from zero to this book, at all.

Working with latest version of WordPress -- this is the perfect book!
Nice small chapters. Easy to read and search. Will keep close as a reference. Very informative. Step by step guide.
This is the most comprehensive and the best written beginning WordPress book that I have seen.
This book is great. Plenty of good examples that agree with what I see on my screen when doing a new install.

WordPress For All : How To Create A Website For Business Or Personal Use, Quickly & Easily – Whatever Your Skill Level by Chris O’Connor

WordPress: The Missing Manual by Matthew MacDonald

WordPress All-in-One For Dummies by Lisa Sabin-Wilson

Smashing WordPress: Beyond the Blog by Thord Daniel Hedengren

WordPress on Demand by Patrice-Anne Rutledge

How to Theme WordPress: From Blank To Beautiful in 2 Hours by Aleks Monahan

WordPress For Dummies by Lisa Sabin-Wilson

The Best WordPress Plugins: 500 Free WP Plugins for Creating an Amazing and Profitable Website by Chad Tennant

Responsive WordPress Themes with Bootstrap: A book for making your Responsive WordPress Themes by Sunny Chanday

WordPress Like Clockwork: How to Run 60 Sites in 60 Minutes a Week! by Mr Chas Newport