Probably this shouldn't be the first book you should buy if you're just getting started with Unity 3D. While you probably could struggle through it, it's really written for those with a good familiarity with the engine and at least some knowledge of C# or Javascript. If you're really new to the process, there are a good amount of beginner's handbooks available. The author pictures chapters as missions and I thought it was a cool way of gamifying my journey through the book.
Unity 4 Game Development Hotshot starts off with the creation of a simple 2D game. Any RPG is incomplete without a menu, and so the next mission(Chapter 2) includes instructions on how to use Unity's GUI class towards achieving it. Chapter 3 covers the creation of a 3D character using shader programming and the custom lighting model for it. Once the character is created, the book moves on to animation and lets you play around with Animation Control, Character control and a little play with the camera.
The next mission is the one which is also my favorite part of the book which was creating a rocket launcher, adding particle effects and switching camera views.
What game would you have created if there was no enemy running for your head. The next mission is all about creating enemy AI which is supplemented by the following mission which guides you towards creating an AI virtual world.
Once your game is made, Unity 4 Game Development Hotshot helps you show your efforts off by helping us save, load, and post the high scores locally and to the server database. As with any programming book, the source files are available online on the Packt site. At over 400 pages, this book is not a quick read and the less familiar you are with coding, the longer it will take you to get through it. Even with a fair amount of Unity 3D experience, portions can be a bit confusing, requiring some rereading. That being said, there are plenty of tips and tricks that you'll pick up, that you can apply toward other efforts, both 2D and 3D.
Tryout the hotshot challenges at the end of every chapter. There is a lot of learning hidden in there.