After a cold spell moves through mid-week I'm going to put in a cover crop on Thursday. I'll be adding a mixture of 50% winter rye, 40% winter oats and 10% hardy vetch. The rye and oats produce tremendous organic matter and the vetch is a legume that fixes nitrogen from the air into the soil for free! Winter oats help suppress harmful nematodes in the soil.
In the Spring I'll get a soil test done and then probably add some compost and other amendments to the soil, depending on what my soil test says, a few weeks before I plant the pumpkin plant.