Passwords should ideally be at least 8 characters long with a combination of capital letters, lower case letters, numbers, and special characters.
All of that, of course, and it must be memorable... If you forget it, you are spewed. I have to change passwords at work every 3 weeks, and it is a pain remembering so many passwords, but you MUST do it.... Do you leave your car keys in the ignition? I don't...