some good guides in my sig.
first lower the ht multiplier to 3x
find max cpu speed: basically, lower the memory divider and increase the htt/fsb to see how fast the cpu could go or to see if it will go as fast as you want. this would likely require bumping up the vcore at times to get stability.
find max ram speed: lower the cpu multiplier so as to underclock the cpu, and put the ram back to the default 1:1 divider and keep bumping up the htt/fsb until you find the ram's max speed.
this will help determine what divider to use when at your cpu's overclocked speed.
but if you want some quick settings for a moderate OC, you'd have to specify which AM2 3000+ you have.. Athlon 64 or Sempron?
Overclocking Help and Links
. Why DRM, BluRay and HD-DVD Blow
Great tools-> OC Bible v1.52 and Guidemania v1.2