Just a very short message to direct you to my article on statistical significance over on the Kissmetrics blog. The emphasis is on intuitive means to understanding the key ideas.
Check Out My Guide to Statistical Significance on Kissmetrics
Fun, example-filled guide, aimed at building intuition
Email outreach, featuring famous people, and buying links?
You need to bake two things into the heart of your web app: keywords and a clever scalable content creation strategy
Separate language from territory; clarify your international site structure to Google