If you're looking to teach yourself to crochet, I'd recommend getting started with an H or I hook and solid, light colored (but not white) worsted weight yarn. For no other reason than because that's an easy combination to work with, being fairly large but not huge. The light colored yarn will help you see your work easily. If you make a maybe 5" by 5" square, you've got a potholder.
Branwyn's links are really good. Also, check out (yep, I'm about to plug it again ladies!)
www.stitchguide.com, which is 100% free and will give you written instructions and also video clips for all the basic stitches and several not-so-basic ones. (It helped me figure out treble crochet and also helped me figure out knitting.) Also, keep in mind that any pattern book you buy will most likely have basic instructions in the back.
For supplies, check out the ones listed and also
www.yarnsale.com (and the parent site,
www.herrschners.com),
www.anniesattic.com and
www.marymaxim.com. Mary Maxim has some "house brand" yarn that's very cheap.
If I might give you a little advice before you start--count your stitches. Always count your stitches. If you don't, you will somehow magically wind up with a trapezoid (diagonal sides) instead of the square you're trying for.
