These books are primo. If you want to understand, in excruciating detail, how to maintain your bicycle, then these are the books to get. The writing is straightforward, and the illustrations are excellent and clear.
The books are full of "recipes" covering this or that task, and provide a complete enough set of tasks that you could completely dissassemble every part of your bicycle and put it back together.
Obviously if your goal is to add an electric motor into your bicycle, you need to understand bicycle construction at a much more detailed level than most people require.
The Bicycling Guide to Complete Bicycle Maintenance & Repair: For Road & Mountain Bikes: The fully revised and updated sixth edition of the best-selling guide to bike maintenance from the world’s leading authority on cycling. With troubleshooting sections to quickly identify and correct common problems, 450 photographs and 40 drawings to clarify all the step-by-step directions so even the complete neophyte can get repairs right the first time, and Web sites and phone numbers of bicycle and parts manufacturers, this is truly the ultimate bicycle repair and maintenance manual. Now better than ever, the newest edition contains the latest information on component kits and carbon fork specifications.