This book gives the most comprehensive idea about LESS pre-processor for CSS. The examples given in the book are quite easy to grasp and implement in your projects.
The features and abilities that LESS provides allow you to significantly reduce the amount of CSS code you will have to write.
In the first couple of chapters the author provides a few tools to show how you can pre-compile your LESS to convert to CSS before deploying to production. Visual Studio developers can use this information in their build events to get LESS converted to CSS on each build.
I also liked the fact that the author marks each section as 'Should know', 'Must know' and 'Become an expert'. It helps me to see which sections I need to quickly glance through if I use this book as a reference guide for LESS.
There are a few typos in the code sample that you need to be aware of. The most common one is the declaration of .less file in the html. The book suggests the declaration to be: