Some Research
http://www.nba.com/analysis/rules_c.html?nav=ArticleList
Above is the NBA’s explanation for the differences between a block and a charge.
This short youtube video shows what a blocking foul looks like.
http://www.youtube.com/watch?v=plo8QrAVpNg&NR=1
Here’s a close call between a block and a charge. You be the judge 🙂
Shane Battier of the Houston Rockets shows how to take a charge.