Using fresh pumpkin is easy and you can preserve some for later if you cook up too much. My simple method is to preheat the oven to 350. Wash your pumpkin, leave it whole. Use a sharp knife to poke several holes in your pumpkin to allow steam to escape. Place your pumpkin on a pan with sides all around (a roasting pan works well) and place in the oven. Cook for at least 1 hour. It is done when the skin gives to the touch and starts to wrinkle. You’ll have to use your judgement. Remove and let cool. The whole thing may slump in on itself and that is ok.
When you are ready, peel off the skin, it should just fall away from the flesh. scoop out the seeds and then puree the flesh in a food processor. I like to freeze in 1 c. increments for later. Here is a great high nutrition dish you can make with your fresh pumpkin: pumpkin quinoa.