And one more for the road: Words to live by

From How To Write A Damn Good Novel, by James N. Frey:

You can kill the spell of identification just as easily as you can create it-if you lose the reader's sympathy for the character. You can lose reader sympathy by having your character commit acts of cruelty to another character with whom the readers identify more strongly or for whom they have strong sympathy. You can lose reader sympathy by having the character make dumb choices-acting at less than maximum capacity. The idiot in the horror story who responds to creepy noises by going into the attic armed only with a candle is an example. You can lose reader sympathy when a character seems too ordinary, is stereotyped, or doesn't struggle hard enough. The reader wants to cheer a fighter, not witness a milquetoast wallowing in, say, self-pity.