Fire in the Valley: The Making of the Personal Computer. McGraw-Hill, 2000.
Freiberger, Paul & Michael Swaine.
This is a fun, very readable history of the PC. All the big names are here - Jobs, Gates, Ellison - as well as a lot of names that are not as well-known but are just as important. We highly recommend this book - you'll learn a lot, & you'll have a good time while you're learning.

The Victorian Internet: The Remarkable Story of the Telegraph and the Nineteenth Century's On-line Pioneers. Walker & Company, 1998.
Tom Standage.
The subtitle says it all! This is an easy, fun book to read. It's short and it moves fast. Along the way, you'll find a remarkable number of similarities between the telegraph of the 19th century & the Internet of the 20th century. Fascinating!