Hi, start seeds of pumpkin in april at 50 deg f, sow 1 or 2 seeds to a 3" pot, when they germinate, remove the weakest seedling and grow on the stronger 1, pot on as needed, before hardening off and planting out at the end of june early july.
They should be planted in humous rich soil that was manured the previous autumn and mulched to preserve moisture in hot summers, but don't let them get too wet, they like a moist but well draining soil, Derek.

Derek's advise is spot on, but I would like to add a bit more.

It helps if you plant the seeds on their sides for better germination.

Also, pumpkins need to be pollinated in order to fruit as they are monoecious, meaning they produce separate male and female flowers on the same plant. In nature this is usually done by bees, but if you find that the fruits are not setting you might have to pollinate them by hand.

The female flowers have a swollen bump which is an immature fruit, at the base and the male flowers don’t have this, so it's relatively easy to tell them apart.

The other thing to be aware of, and I'm assuming here that you took the seeds from a shop-bought pumpkin rather than seeds bought from a garden centre, is that the fruits might not come true and you might end up with a pumpkin that doesn't look anything like the parent fruit, but this is all part of the fun of growing plants from seeds, you don't quite know what you will get :o)

AS above Plant seed in the spring in a greenhouse April – May - 2 to a pot –thin out the weakest plant out when temperatures grow – Also you may plant out into the garden once the ground warms up -REMBER don’t forget they will rot if left on the ground – Raise them up of the ground. Ken