To cook the pumpkin, (I do this with pie pumpkins, jack-o-lanterns aren't as flavorful) remove seeds and strings, cut into quarters and lay skin up on a baking sheet. Bake in a 400deg oven for an hour or until the pumpkin is tender. Let it cool, then peel it and puree in a blender or food processor. I make a nice smooth puree without water, sometimes you'll need to add water if it's too chunky and won't puree. Voila!
Now make stuff, like pumpkin bread, pumpkin pie, pumpkin scones, feed it to your bitty (I give him chunks as I'm pureeing, he loves to steal them from the pile).
Each pie pumpking is usually good for two cups of puree. This means one pie, or two loaves of bread, or ...