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
Ways metrics mislead you; how to overcome low reach/low quality score/high CPC etc.
A deep guide to developing a loving relationship founded on clean data, great communication, and appropriate caution
The general principles of targeting followed by a tour of the available options on the major platforms