Overclocking

For overclocking it varies.

A couple questions to help answer the "should you".
Is your computer under performing and you want a bit more or just "cause"? If it's under perfoming Overclocking may not help it could be an IO issue. but just cause doesn't hurt.
Do you have the proper cooling capacity? If you have stock cooler or a cheap air cooler. Don't. It will just cause problems.
Do you have the power supply for it? Seen a couple people try to overclock would power supply that could barley support the PC as it was.