Spread a product called Ronstar on your lawn. It's a pre-emergent herbicide that lasts all season. Grass will flourish in your yard, but weeds will not germinate. You could take a handful of weed seeds a throw them in your yard and nothing will happen. One application after the snow is gone and you don't have to worry all spring or summer. Your neighbors could have all weeds for lawns and you'll have all grass.
It won't kill already growing weeds - you'll have to kill them with a weed killer. It just stops the germination process, so no new ones will grow.
You can find it at some landscape supply stores, you'll have to call around. John Deere Landscapes carry it. You can also buy it online. It usually runs about $125 for a 50 lb bag. Not cheap, but not bad either. The stuff works great.