should I warm the soil in my vegetable plot?
I have read that there can be benefits but is it really worth it? Also if I do should I use clear or black covering?
You can use either black polythene or polytunnels to warm the soil. It does have benefits as it leads to early germination and earlier cropping if kept covered with a polytunnel. Covering early crops with fleece gives some protection against frost as well.
I think it is worth it. I have a very lightweight cold frame, timber and polycarbonate that I place over the soil for a week or so before planting, and keep in place for a while afterwards and then move it on to another area.