I am a engineer who needed an intro into computer networks for my new job. Among the ones I looked into (Freeman, Held, the SAMS series etc ) I found this one the best by far.
First, the writing style is extremely friendly and casual, you feel like the man is speaking to you directly.
Second, I found the contents quite up-to-date for my purposes, which was to learn the basics and be ready to go further. This book helps you understand data coms based on the OSI model.
It prepared me to tackle more advanced books - at the moment I am in R. Perlman's " Interconnections".
Excellent.