How to write a bestselling fantasy novel. So now we all know. (Link from dancinghorse.)
Though this is just the crash course. If you’re serious about writing a bestselling fantasy novel, the book to read is still Diana Wynne Jones’ Tough Guide to Fantasyland.
However, this short take does hit on one of my primary gripes with certain sorts of high fantasy, one that for me goes all the way back to Tolkien:
Note that in Fantasy Lands the concept of reform or rehabilitation is unknown. All allies, minions, vassals and instruments of the Enemy must be summarily killed even if they served their master primarily out of fear.
Because, you know, even the war of the ring could have benefitted from the help of a few rescued or repentent orcs or haredim.