I may not represent the "typical" target for this book as I purchased it strictly to review CompTIA's Windows troubleshooting protocols; I'm sure my mindset of "let's nuke the entire site from orbit, it's the only way to be sure" when a computer encounters any moderately complex problem is probably not the most conventional (at my job I've found it more practical to keep a backup image on the network). Despite that, I've ended up reading it (mostly) cover to cover; no small feat considering it clocks in at 1150+ pages, and I think I've walked away with more than I expected.
Mike Meyers takes a "let's start at the bottom" approach that I find ideal since I think it's easier to understand a complex subject when I get the building blocks first. I'd say the first quarter to third of the book is focused on the overview of the PC, its basic technology, and the evolution that brought us to the present day. Every chapter begins with a section titled "Historical/Conceptual" in which he will review the basic concepts of how the technology works, then become more concrete. For example, over the course of a few chapters the book covers the basis of computer language (the binary system) and how the processor physically communicates with the rest of the computer. He then applies this to describe the Intel 8088 processor, an old and very influential design, then explains how that design evolved over time to incorporate new innovations and discoveries to bring the reader to the present day's Intel Core series. The middle of the book moves into bringing the fundamentals together, and towards the end circles back to advanced/esoteric hardware implementation and networking.
Some of the material in these sections may seem to have little bearing on the A+ exam, but it's critical to really knowing the basics of computers and how they work; after all, you can't fix something you don't understand. Generally, beyond Historical/Conceptual comes "Practical Application" which will delve into implementing and troubleshooting. I found the tone throughout well balanced, with the right amount of technical detail mixed with analogies where necessary to promote understanding, and enough humor keep a reader awake. There are also a fair amount of Windows screencaps and diagrams when discussing muddy or dense subjects. Every chapter wraps up with a brief quiz to ensure you've picked up the essentials, and closes with a section titled "Beyond A+" to further expand on relevant topics or suggest continued reading or practice.
Later chapters move into what you would expect - Windows internals, hard-drives, LANs, networking, mostly with the same thoroughness as earlier chapters, though at times it does feel like the author is simply rattling off information from a list - I found the section on Windows Group Policies especially tedious, but that's Group Policies for you. Some of the analogies I thought might seem belaboured to a novice; the CPU as a man in a box flipping switches I thought was possibly confusing (like, so simple it's actually kind of obtuse) to someone who doesn't already know a bit about binary and electronics.
If you're considering purchasing this book as a beginner looking to pass the A+ exams, I wouldn't think twice. I think this alone would be enough to pass the exams, provided you spend the time needed to actually practice what you can. The specifics the book gets into about troubleshooting particular problems (and the decent index) would also make this an ok reference to have lying around a shop, though not my first choice.
I know when you're first starting out, it's hard to be patient, especially when you're making your way through a tome as hefty as this, but don't skim and don't think this book is "beneath you" (my mistake initially) and you'll have a good amount of knowledge under your belt by the time you hit the end. A+ is probably your first step, it's important that you get your first step right.
Beyond A+ comes the brunt of computing today - networking. This same author's "Network+" guide book, written with the same attention to detail, would seem to be a natural starting point but it might also be beneficial to go hands on first and try "Computer Networking: Internet Protocols in Action"; it comes with a CD containing packet traces you'll be following with an analyzing program called Wireshark. I'd also suggest a classic, "TCP/IP Illustrated, Volume 1" if you really want to get how networking works. You'd also do well to check out the catalog of No Starch Press, and bookmark them; you'll be coming back to their heavy stuff in a year or two.
