Linux will see the "boost", if you don't crash and burn that is.
A little overclocking doesn't usually affect stability, but when you start to push the envelope it's a good idea to test thoroughly after each incremental increase. Bump it up one step at a time and test; when your system starts to get flakey, back it off one step and you're maxed out. There's even a Knoppix based Linux distro called overclockix specifically for doing this: http://overclockix.octeams.com/
Just be aware that pushing your PC's limits will generate additional heat. Some overclockers spend more on cooling systems (water, peltier) than I did on my last mobo and CPU combo.