The Not so Idiots Guide to IPSec looks to be an interesting read. Okay, okay it's really called An Illustrated Guide to IPSec, but I liked my title better. Anyway, it's got squiggley lines to help you understand IPSec so it can't be all bad.
On to flashing dots: If you stare at the center of this image for long enough something amazing will happen.
(Illusion via Random Good Stuff)