Well... the tutorial I saw was for building a bass pickup, but it said all you really need is a long spool of wire, a few popsicle sticks, some neodymium magnets, and loads of patience, besides the wax with which to pot it and the cover. Of course, it was also for a single-coil bass pickup, so I figure humbuckers are probably much harder... But thank you for your answers.
Now for a (possibly) more tricky question... I saw in the tutorials here that you can make a blend knob out of a pot (I forget whether it was a volume or tone pot), and got to thinking. See, I want to make it so the middle pickup can be switched on and off by itself, while the other pickups are on or off depending upon the setting of said knob. (I would also like to have the middle pickup sort of average out the volume between the bridge and neck pickups, if that's possible, but that would just be a cool little extra that I probably don't really need.) Could I use a push-pull pot for this switch and the blend knob, and if so, how would it have to go? (I'd also like to put one of the DIY sustainers explained in Ansil's tutorial in it, but can scrap it if advised to. [i'm still in the planning stage--good thing my project's not due until next year!])