Bold Visions is more of a starter guide to digital painting than a bible.
It goes through the core art techniques such as colour, lighting, composition, research, materials and stuff like that. The good thing is all these concepts are explained clearly with great illustrations as examples.
The techniques and tips are presented in a pointer style as well as in the form of several step-by-step workflow screenshots. These step-by-step processes take a look at how Gary Tonge creates his digital sci-fi illustrations, as well as explain the considerations he takes to achieve certain effects -- sometimes dictated by clients. These are not tutorials that go into technical software details like changing opacity jitter and settings.
This book is recommended to beginners to digital paintings, especially fantasy and science-fiction artists.
If you're looking for step-by-step tutorials into digital painting, you might also want to check out ImagineFX's Fantasy Workshop. The tutorials there are slightly more in depth.
There are more pictures of the book on my blog. Just visit my Amazon profile for the link.