I need to learn some new stuff relevant to todays market, who do you recommend?

In the past I have invested in quite a few courses, all of which brought me money retailing and wholesaling. However I need to go back and refresh my self to move forward. Who do you guys recommend for advanced, experienced people in buying and selling, private money and wholesaling?

A couple years ago I noticed Richard and Dan Doran. Any thoughts on those guys? They seemed to have survived the downturn. Any recent success with their info?