Overclocking your Raspberry Pi is ridiculously easy because the values are simply stored in a text file on the root of the device, they can be easily edited and changed via Nano or VI, and if you brick the device or get a kernal panic, you can change the values by plugging your SD card into a computer and editing the file there.
Here I’m going to show you how to push your Pis CPU up to 850MHz, it is possible to hit 1GHz, but this involved overvaulting which voids your warranty, can damage your chip, and reduce it’s lifespan. It is safe though to clock your Pi up to 850MHz without the need to overvault, but if you do wish to get it up to 1GHz, I will supply you with the config further down this post.
over_voltage=6
arm_freq=1000
core_freq=500
sdram_freq=500