go to sierratradingpost.com & order whatever cycling socks they have on sale...

seriously, though, the concept of cycling socks - as opposed to regualr socks - is that you do not want your sock retaining sweat while you ride. Cotton retains moisture, wool and synthetics usually don't... so, the less cotton, the better. In theory. Wear whatever's comfy & fits your budget. Check out thesockguy.com