A+ Certification is going to quiz you over the basic operations in Windows and where to find relevant information about the system/OS/drivers.
It is going to quiz you over things like CMOS, BIOS, RAM and CPU installation and settings, PCI/PCIe function and benefit, USB, IDE/SATA and RAID 0,1,5,10. It will also quiz you over GPUs and compatability, as well as PSU's and the testing and installation for all the aforementioned things. Diagnosing/troubleshooting problems is a big part of this as well, so knowing what symptoms are connected to which piece(s) of hardware will be key for you. A+ is not just building, it's repair and troubleshooting as well.
Networking is another thing you'll need to know. Become familiar with Novell to some degree, be sure you understand windows network protocols, installation, and setup. Knowing how to properly crimp and install connectors on network cables is something they ask about (GrWh/Blu/BluWh/Grn/BrWh/Brn/OrWh/Or...iirc)...also, you'll need basic diagnosing and setup skills for wired/wireless networks.
I do recommend an A+ Study guide...they actually make an A+ for Dummies I believe which would likely be good if some of those concepts are very foreign to you. The test is long and comprehensive. Though I haven't retested in years...I doubt that other than software/hardware nuances much has changed.
Good luck