Learning conversion as part of your internet sales training

I have just started a new internet business and have been reading up on the finer parts of online sales. I have previous offline sales experience that I need to adapt to suit the internet. I am determined to learn as much as I can about internet sales training. A friend has provided me with some resources including how to setup stats to track my orders. He stressed the importance of tracking conversion and trying several different sales pages to see which one is more effective.