Earn From Stock Option

I wonder how much could people earn from covered calls. I always heard people talking about stock option; they told me they earn some amount from the stock market already. Although I am quite interested to know more about it, however it sound very complicated to me. I think if I really want to invest into stock option, I will need many time to understand how it is working. Nevertheless, I think if I could find some website like Power Options, then will save my times to study on it. They claimed that their website provided the best way to find, compare, analyze and making money on option investment. They offer 14 days free trial some more! I think I better get myself register and start to free trial lesson.