The Dark Lord's Handbook is a fun and witty romp on the dark side. The "Handbook" is essentially a manual for being bad and being good at it. Those pesky heroes keep killing the bad guys, and Evil thought perhaps this manual would keep them alive and doing his dirty work.
One of the best things about this book, on top of the great sense of humor and excellent lack of taking-itself-seriously (I mean that as a compliment), is its unique concept. It's also a bit of a farce, in that lots of fantasy characters show up for the party.
The Dark Lord's Handbook brings to mind your typical, cartoonish good guys and bad guys who are as good or evil as they come, but just can't seem to get the details right. These include your Inspector Gadget, Gargamel (the Smurfs), Team Rocket (Pokemon), and others. I am not suggesting that this is a book for kids, but I am suggesting that adults may get a kick out of seeing these highly entertaining (and not entirely put-together) goings on between good and evil. And if they're familiar with fantasy, they'll get another kick out of seeing common fantasy tropes used in entertaining new fashion.