SOmething everyone on my plot does is plant a squash (usually a pumpkin) in their compost heap. Make your last top up atleast 4 weeks before you want to plant, then make a hole in top of your heap and fill with soil/pot compost, and plant your squash into it. All the goodness and heat is used, and at the end of season you just break the plant up and dig it into the compost and next year use it on the plot :)
They get some amazing specimens this way, because squashes are very greedy! Your way of planting sounds fine to me. Thats how I did it last year. Some suggestions would be to knock a good size stake in the ground by the plant base, because once its grown its heck to remember where it is to water!! Some people stick half a bottle in for watering, can work but can be overgrown by the plant!!! If your gonna use plastic membrane have some times or something to raise the squashes off the ground stop them rotting underneath, even give em a half turn occasionally.
I think squash is a general term, whereas pumpkin is specific for the hard skinned type of fruit. But thats only my guess!
