read each sports sabermetric type forum. believe it or not, much of the best analysis is done for free and in public by people who have no interest in betting but simply enjoy analyzing their favorite team or sport. stand on their shoulders, think about how to apply those ideas to betting, and do it yourself.
similar to the previous suggestion, subscribe to
jqas and think about how to monetize the rare nuggets of wisdom you'll discover.
most likely the end result is that you'll invest hundreds of hours learning useless information, build a ****ty model, and lose.
either way, never share what you learn/discover.