Resources
Take a look at the Cornell Home Gardening Vegetable Guides for Corn, Squash, and Beans:
Corn - http://www.gardening.cornell.edu/homegardening/scene05f6.html
Squash - http://www.gardening.cornell.edu/homegardening/scene11f1.html
Pole Beans - http://www.gardening.cornell.edu/homegardening/scene8f63.html