It's all singular to your CPU because of the whole "silicon lottery". There's not a really standard max clock for your CPU - it's really about going in and slowly clocking it up until heat/instability forces you to stop pushing the chip. Of course, you can look online and see what a good average clock for your CPU would be (affected by motherboard, CPU, and CPU cooling solutions).
Also, if you're overclocking you'll need a reliable CPU cooler as well as motherboard.