If you're going to go to the trouble of cooking down pumpkin yourself, you really should take advantage of the opportunity to make your very own yummy roasted pumpkin seeds. I far prefer home-cooked seeds, simply because the ones you can find at the store are often so salty.
Before roasting your seeds, you'll want to separate the seeds from the goopy center of the pumpkin. This might take a while, but it doesn't have to be perfect! If one or two bits of pumpkin get in, it won't hurt anything.
Once you have separated your seeds, wash them, and put 1-2 tablespoons of olive oil over them (assuming you have multiple pumpkins worth of seeds; if you just have one pumpkin's worth, used MUCH less). This keeps them from sticking to the pan, and makes them taste really good!
Spread the seeds out on a baking sheet (or two. . . ). The seeds can be touching each other, but you don't want them sitting on top of each other. You might have to make multiple batches if you processed more than 1-2 pumpkins.
Bake for 15 minutes at 350 degrees Fahrenheit. At this point, you'll want to check on their progress and flip them as best you can.
Bake for 5-10 more minutes, then take them out. Spread the seeds out on a towel (which you don't mind getting a bit greasy), and salt.