How much can I overclock <insert thing here> by?
This is by far the most commonly asked question (right ahead of 'what is overclocking'). The answer is that nobody on the planet can tell you. Why? Because each component connected to the entire system as a whole will place limitations on the amount of overclocking you can do (this is intuitive: you have a good processor but a crappy motherboard = you wont OC worth crap). Another reason nobody can tell you -- even if they have the exact same specifications as you -- is because two identically configured machines can have wildly different ceilings ... call it luck of the draw as far as the manufacturing process goes.