The Seminole pumpkin (Cucurbita moschata) is actually closer related to butternut and calabaza, than a real pumpkin. They usually grow in a more pumpkin-like shape than butternuts. The vines are aggressive and fast growing, achieving lengths of 20 feet or more. They like to climb, but the fruits usually pull them down.
Soil: Prefers rich soil with lots of organic matter and plenty of lime. Fertilizing also usually helps. The best vines usually volunteer from compost piles. Mulch heavily to control annual weeds and conserve water, but keep it half a foot back from the origin.
Water: These need plenty of water when they're starting out, and may need irrigation throughout, depending on your soil's capacity to provide water. Some people don't care for their vines at all, and have good production. Avoid overheard watering, especially late in the day, as moisture can encourage gummy stem blight.
Sun: Full sun is usually recommended, but we find the vines wilt most of the day. Light shade would probably help reduce wilting time and therefore improve growth. Fruits can be sunburnt on hot summer days, if the older leaves that used to shade them wither away. We have solved that problem by intercropping with sweet potato.
Cold: This is a fairly long season squash, so I would not recommend a fall planting, but they could succeed if we don't get any freezes till real late in the year.
Propagation: Seed. Every vine seems to be a little different. Take care not to cross with less rugged Cucurbita moschata, like butternuts. Plant as early as possible.
Pests: It resists powdery mildew, though its white leaf splotches are often mistaken for it. It resists vine borers, but not completely. Check for holes spilling wet sawdust, usually at a leaf or tendril joint (especially if a portion of the vine wilts). Split open the stem with a knife and remove the borer. A concentrated rotenone/pyrethrin spray can prevent them except that rain washes it off. Another type of borer infests the new fruits and flowers. I kill all I can to prevent their reproduction. They only attack the very young fruits, and seem to come in waves. You should get some production between the waves. A green caterpillar with white lines webs leaves together, rolls the edges, and especially favors the growing tips. They can be very destructive. BT spray or powder should control them. Seminole pumpkins are susceptible to gummy stem blight if you mulch up to the base.
Other problems: Will invade the rest of your garden and all your neighbor's yards.
Harvesting, storage, and preparation: I like to wait till the stem turns brown just in case it might get a bit sweeter. They can also be eaten green, like a summer squash. Putting wood under the fruit can prevent damage from the ground. Some people leave them out long after the vine has died and they stay remarkably healthy. I've had shelf stored pumpkins last more than a year. They make excellent pumpkin pies, pumpkin soup, pumpkin bread, and anything else you might use a butternut or pumpkin for.
More photos on Flickr: https://www.flickr.com/search?sort=relevance&text=Cucurbita%20moschata
pdf - Seminole Pumpkin Information Sheet (to print out)