CompTIA Network+ Certification All-in-One Exam Guide, Eighth Edition

I took the N10-009 exam and got 835/900 using only this and flashcards for ports/protocols. Can't have a better review than that, even for a slightly outdated guide. They do a great job breaking down concepts with lots of visuals. Most of it I read on my kindle–it was even entertaining, for what it is. Highly recommended.