It is a great sign that @SEOMoz included Conversion in their grand plan for Content Marketing. This infograph considers conversion a key component of content marketing, but in my upcoming book on conversion I make content a key part of conversion marketing. Different approaches, same result.
This is a great place to start if you're not familiar with testing. This illustrated guide tackles the simplest to the most advanced testing methods without leaving beginners in the dust. Well done.
Enjoy the Infograph.