Book excerpt: Reading a blueprint is like reading a road map. It tells you exactly what you are required to build. Read it wrong and you will build it wrong -- and that can be expensive. This book explains how to read and interpret all types of electrical drawings and diagrams used in residential and commercial construction. There are details on electrical floor plans, lighting layouts, and schematics showing single line and block or power-riser diagrams for wiring circuits. Learn how to lay out an electrical project, what to look out for in dealing with construction specifications and drawings -- especially in terms of today's technology, how to use an engineer's scale for developing and reading site plans, and how to make up and use panel board, connected-load, and other schedules.