I found an interesting series of pages on Seymour Duncan’s website that give an introduction to pickups. It’s called Pickups 101 and it covers the basics of pickup construction, different types of pickups and their sounds. It’s a good guide to a subject that is of fundamental importance to electric guitar players, and it’s a good read for anyone who doesn’t yet know all of the ins and outs (or Norths and Souths) of pickups.
I have two guitars with SD pickups. My Epiphone Rosso Corsa has the Slash Alnico pickups, and my Chapman Ghost Fret (pictured below) has a Duncan Distortion (bridge) and a Seymour Duncan ’59 (neck).