More-with-Less, with its emphasis on African and Asian cooking and whole grains in other ethnic contexts, was also our earliest introduction to food outside of the stereotypical American food groups.
Lately we have been turning again to More-with-Less, but this time it's on the web, and it's helping us to eat seasonally. Simply in Season is a web resource companion to some of the More-with-Less printed materials. It has a long list of fruits and vegetables and some key points on when they are in season, and how to use them.
They follow the garden seasons common through most of North America, and we've found this a very helpful introductory resource as we try to eat more seasonally and locally.
They also have a weekly recipe that highlights a seasonal vegetable.