I have just read an excellent article on the pros and cons of cultivating your vegetable plot. The one thing that I particularly picked up on was that autumn (fall) cultivation can actually do more harm than good to the soil. In general, I would agree with this statement but here in the UK it is possible to do some winter cultivation provided that the soil is not too wet, this is especially useful if you are just starting out and have heavy clay-based soil as the frosts etc will help to break the soil down into more manageable chunks. But once you have got your plot established I would not even do that and wait until later in winter or early spring to cultivate. The full article can be found here at growveg.