If you followed along in the first post and roasted yourself some green coffee beans into a roast you want to try - or if you purchased some (fresh roasted I hope!) coffee in whole bean form - you need to get it into the ground state before you can extract the coffee goodness. Typically to do this you'd use a coffee grinder. Unfortunately for us coffee snobs, most of the grinders available to us mere mortals are of the spinny blade type. These don't grind the coffee as much as bash it into semi-uniform sized chunks. Some say the blade type also heat the beans slightly, thus destroying some of the goodness of a freshly roasted bean. If you can get one, try to find an offset burr grinder, it will produce a more consistent grind and won't subject your precious coffee beans to a thrashing at the hands of a hundred mph metal blade. They are more expensive, no doubt, but Target sometimes sells one for around $25.00 that I've been using for the last 6 months that is decent and has an adjustable grind fineness setting that seems to work pretty well. If you want something a lot better head over to Sweet Marias and see what types of devices they have.
I've also heard that you can get a burr grinder attachment for the front of a Kitchen Aid stand mixer (a fact that's not a surprise since I think you can get a tablesaw attachment for those mixers). I've never attempted to use one of these although we do have one of the Kitchen Aid mixers. From back in my home beer brewing days I heard good things about the burr grinder attachment for the Kitchen Aid - to properly brew whole grain beer from scratch you need to crack the barley but not grind it. So you need a grinder with some precision. I'd love to hear from someone about the grinder attachment.
Depending on the type of brewer you'll be using will determine the fineness of the grind. For a pressed cup like you'd make with the aeropress or a french press, you'll want a finer grind than you would for a drip maker (bleh, generally). Experiment a bit to see what suits your taste.