Overclocking MSI P6N SLI Platnium

I built this computer a few years ago and it is getting old. I would
like to squeeze another year of life out of it performence wise before
I have to upgrade. Games are starting to run slow.

I just bought a new video card so whatever I do I dont want to OC it
or do something that would dry the video card.

Can someone tell me some moderate settings that will improve my
performance but not shoot my house to the moon. I searched groups
looking for some settings prior to posting, but most of what I found
was people pushing it to the limit... I am just looking for some
moderate improvements that I wont have to worry to much about heat and
will have a lower risk of damaging the board / proc

MSI P6N SLI Platnium MB
E6600 Proc
Kingston Memory 2GB

Video Card - GE Force 260

Cooling... good size case, 4 case fans,clip on fan over north bridge.
processor fan is the oem one that came with the proc.

JD