do damage, but only if you raise the voltage up too high or let the temps raise too high.
Just dont be silly and you'll be fine.
Also, remember, your FSB can only go as high as 2x the rated speed of your RAM.
For example, my RAM is DDR2-800, so that limits me to an FSB of 1600 (Which sadly limits me to a maximum overclock of 3600MHz, but lets not get into that).
EDIT - Another tip, download 'Orthos' and let it test your system whilst overclocking. If you get any errors, reset the overclock and try something lower.