First of all, welcome to the forum dragonlotus!
I'm fairly new too but I'll give this a shot anyways...
After a quick google search, I belive kde 3.3 comes with the theme manager pre-installed in the control center, so first check your version and see if it is allready there. If it's not, you can download it
here.
Download that file and extract it, and then look at the file 'INSTALL'. See if you understand it, and if you don't, just ask.
Yours,
antiNeo