Protect the soil of your empty vegetable bed and keep out wayward weed seeds by covering the beds with leaves or straw. Avoid weedy hay as this only introduces millions of weed seeds. This surface organic matter also can encourage beneficial earthworm activity.
There's a window of opportunity for mulching because you want to wait until the ground freezes so you don't give rodents a hiding place too soon, but if you don't mulch before the snow accumulates, it won't get done. If we could rely on constant snow cover, mulching would be less necessary, but in the absence of that protection, we need to provide a winter blanket. Some plants such as coral bells, delphiniums, oriental poppies, iris, violas, and sedum are better off without any mulch, especially in winter, when it can compact and encourage crown rot.
Before snow flies and the ground freezes, November is your last chance to plant garlic bulbs, to dig gladiolus to store indoors over winter, and to plant fall bulbs. If you don't get your spring-blooming bulbs planted, pot them, then store indoors in a cool place (40 degrees is ideal, as in a spare refrigerator or cold root cellar), just don't let them freeze. Then, anytime after 12 weeks you can bring into warmth indoors to force into bloom.