Hands down, the best A+ book is the A+ All-in-One Study Guide by Meyers.
If you're just starting out in IT, I'd wholeheartedly recommend getting the A+ and Network+. I might even recommend picking up a client OS certification, such as the MCP on Windows XP and/or the MCTS on Windows Vista or Windows 7... and no further until you get some IT experience.
With the exception of the entry-level certifications I've mentioned above, certifications are designed to show employers what you already have experience doing... not what you want to be doing. So I would recommend holding off on the MCSA/MCSE/MCITP certifications until you've been doing server administration for a few months, and I would recommend holding off on the CCNA until you start helping out with Cisco router administration in a real-world environment.
Even with a bunch of certifications, you won't typically be allowed to jump right in to server or network administration. Those jobs are given to people who have IT experience. Generally, the career progression for an IT admin is desktop administrator -> server administrator -> network administrator. I've seen far too many people jump straight for the network admin carrot, get frustrated because they aren't hired for those positions, and give up.
Getting higher-level certifications without experience can actually make it MORE difficult to get employment rather than LESS difficult. Companies with higher-level jobs will pass you over because you are underexperienced for those positions, and companies with lower-level jobs will pass you over because you are overcertified - after all, they don't need a guy with a CCNA to do basic desktop support. Someone who is overcertified is a "flight risk" - they'll leave as soon as something better comes along, leaving the employer to find, hire, and train someone all over again. Rather than take that risk, they'll simply hire someone who is not CCNA certified and who will probably be cheaper for them to hire.
I've got 14 years in the IT industry both as a network admin and as a creator of IT certification training products. I hope my perspective can give you the insight you need to quickly and confidently climb the IT career ladder.