Hi, i am thinking of taking a test for the A+ certification however i don't know exactly what needs to be known and if im lacking any knowledge.

Heres the deal, Im 16, i know how to put together computers install OSes and any software/hardware. I know intermidiate Windows Xp troubleshooting. I know some of the basic units of data measurement (the "Byte", all divisible by 16 i.e. 1 gig= 1024 mb, 1 mb = 1024 kb etc.) and speeds(PC3200=DDR400, 1000mhz= 1 ghz). I know how to set up a basic network (1 router and 2+ comps/switches/printservers). I also know some other little things but too much more to list. I would like to know if anyone knows of any websites with free "pre-tests" or Test prep information specifically regarding this topic or even a thread on this fourm if i happened to miss it and if there is an age requirement. Any Help given is greatly appreciated.