Legumes are a beneficial cover crop because after you harvest your peas, or beans, you till the foilage of said Legumes into the soil. This enriches the soil. You will have to have a rototiller regardless if you get someone to till it up with a tractor.
This time of year, after tilling the ground, you can rake leaves and add to your ground, and till those in too.
Anyhow, while you could plant some cold weather crops, you want to get your soil ready for spring.
Cow manure, as RWalls said is great too. Do not use chicken manure where you plant tomato's, this causes too much potassium...or is it nitrogen..can't remember...Also read up on what kind of fertilizers you will use for different crops. A 5-20-20 is best for Tomato's, while a 10-20-10 is best for potatoes.
You'll probably want some sweet corn. We use triple 13 for that, and some crops like corn you will "side dress" with additional fertilizer later in it's growth.