the byc website actually has a breed index that explains it pretty well... you can read through the breeds...
if you want a good overview...
white leghorn is probably the best white egg layer.. they will probably give you a egg a day almost throughout the year...
and a lot of breeds are good brown egg layers.. the barred rocks, rhode island red, australop, new hampshire, delawares, and any type of production layer like red sex link (red stars), black sex link (black stars), golden sex links (golden comet)
hm.. yea there's a lot of good brown layers...can't think of more off the top of my head..
and if you want colorful eggs you have easter eggers and ameracauna
dark brown eggs you have the marans and barnevelder
good luck chickens are addicting.. i would read through the breed indexes...
http://www.ithaca.edu/staff/jhenderson/chooks/chooks.html
here's a link that's a good chart and it shows you egg production