Windows 7: What should I know before overclocking this graphics card?

I'm running Windows 7 64-bit.
GPU: Gigabyte AMD Radeon HD 7850 (2GB GDDR5)
I currently have 2 in my PC. I replaced my bigger card (that often got rather hot) with the two smaller ones and now my computer stays at a low temperature even while playing high req. games.
I've never overclocked, this will be my first time. I know this card is meant to be overclocked and has very good cooling. The Gigabyte even comes with software called Easy Boost that overclocks and change card settings easily.
Before using Easy Boost to overclock, what precautions should I take? Are there dangers involved?

There are several precautions I know of, is that if you overclock the card to high it could damage it, and ATI warranty does not cover the overclock.

First thing you need to know is, "does my case have a good airflow" Then you need to take baby steps, overclock by 5MHz each time while testing for stability and artefacts on the screen, also monitor temperatures, moderm GFX cards can handle upto 105C b4 you will start to run in to problems, even then it will down clock the card to cool itself.