There are lots of patterns:
http://www.google.com/#sclient=psy&hl=en&site=&source=hp&q=crochet+sock+pattern+free&rlz=1W1ADFA_en&aq=1&aqi=g3g-m7&aql=&oq=crochet+sock+pattern&gs_rfai=&psj=1&fp=c341562a61b59af3
AND
http://www.crochetpatterncentral.com/directory/slippers_socks.php
AND
http://www.crochetpatterncentral.com/directory/socks.php
Do a search -- www.google.com and on search line type
in crochet sock patterns and a list will come up and
just click away.
Hope these will give you a start.
Good luck.