As you accomplish the tasks throughout the book, you'll construct many projects while learning the key circuitbuilding principles and techniques. Find out about measuring and testing, maintenance and troubleshooting, cables, connectors, how to test your stuff, and more.
This is the part where you start building real circuits! There are many types and styles of circuitbuilding. Some are best suited for temporary experimentation; others enable you to make permanent circuits for the ages. This part helps you decide which approach is best for the job at hand.
If you're not sure of your knowledge start with a really basic book such as "Arduino for Dummies" it will introduce you to basic electronics and you can then get into something something deeper as needed. If you're serious you could then get yourself a decent text book.
The heavy electronics theory books tend to be a bit more pricey than standard books. The two books I have listed here should be worth the investment though, if you see yourself working with electronics for many years to come.
Wiring the basement, one of the funnest projects that finishing a basement requires. Make no mistake, this is no small project and it will test your basement finishing perseverance. But if you commit to wiring your basement yourself, you will be rewarded with a completed project that required both creativity and ingenuity.