Here are a few Stack videos and an old school drill:
Old school ------ Hit a basketball off of a tee.
http://www.stack.com/video/772...anded-hitting-drill/
http://www.stack.com/2012/05/1...c-forearm-exercises/
http://www.stack.com/2012/10/01/bat-speed-drills/
http://www.stack.com/video/905...with-gordon-beckham/
http://www.stack.com/video/776...reebok-vector-o-bat/