new techie…

i have some questions to ask and i’m not sure what website i can go to to ask computer-related
questions. The first question is, can u go from say 128 mb to 512 mb of memory in my cpu? which
one is bigger out of mb, kb, gb, ghz, etc? and are they referring to the same thing and just one
size bigger than the next or does one have absolutely nothing to do with the other? are all cpus
compatible with any monitor and vice versa as well as harddrives, cd-w, cd-rw drives? i’d
appreciated if u could answer my questions if someone else could. thank u. Sam