cooking pumpkin is fairly simple it depends on what you want to do with it. If you want to use it in a pie and were looking at using puree then this should help. cook the pumpkin till you can stab a knife in to it with out too much effort it should be soft yet still firm. now drain the water off the pumpkin add a table spoon of butter and a pinch of salt and pepper and mash one you have mashed the pumpkin add a dash of milk and keep mashing till it is smooth and fluffy. don't worry if you cook it too long as it will still turn out well. if you wanted to roast the pumpkin then cut it into about a 2inch cube drizzle a bit of olive oil over the top add some garlic salt and mixed herbs or even just some rosemary and bake on 175degrees centegrade about 300F. keep them turning and wait until if you put a knife in to the pumpkin it is firm yet soft.
Hope this helped, Trev