Pumpkin is the squash that we associate with fall, Halloween, and Thanksgiving. It is however a most versatile vegetable full of health giving properties, such as vitamin A. Its bright yellow to red color and abundant flesh is a boon to dieters as it is also low in calories and fat free. There are two types of market Pumpkin. Pie Pumpkin are smaller and sweeter, with a drier flesh. Carving Pumpkins have a bright orange color, and a less dense flesh with more water content than the Pie Pumpkins. They are grown primarily for carving at Halloween. They can be sliced and sauteed or simmered for a vegetable dish. The seeds from both types of Pumpkins are loaded with great nutrition as well, and should be toasted and enjoyed.

Fruits are harvested at full seed maturity, but generally do not store as well as the winter squash types. The flesh is generally a little too coarse and strong-flavored for eating so most 'pumpkin' pies are made from winter squash. In earlier times, pumpkins were extensively used as livestock feed.

As with winter squash, pumpkins are a diverse group. Small, classical jack-o-lantern types such as Connecticut Field and Kentucky Field are C. pepo, while large pumpkins such as Atlantic Giant are C. maxima and should more correctly be called winter squash rather than pumpkins.
Cushaw, Tennessee and Sweetpotato (the last is used for canning, but does not store well) types are Cucurbita mixta.

Here are a few great pumpkin links:

http://www.thepumpkinfarm.com/

http://server11.hypermart.net/cheffette/frtandveg/pumpkin.html