You don't need a book. You just need to build a hello-world application with the Bootstrap CSS/JS code, using one of the layouts they provide as a starting point. Then just use the page of Bootstrap demos as an a la carte menu as you find yourself needing UI features.

The Grid Systems book that was recommended earlier is a better bet if you're a typographer or graphic designer, and particularly if you're thinking about designing novel grid systems. But you're not doing that. The Bootstrap grid is trivial and does not require any background in design to use.