I recently read somewhere that vinegar sprayed onto weeds will kill them. I would like to try it but don't know what kind of vinegar to use or if it needs to be mixed. Can anyone help me with this?

Yes, white vinegar is an excellent weed killer. Quite cheap, too AND environmentally healthy. I buy it by the gallon at Costco (cheaper still) and use it full-strength right out of the bottle. I put it in a garden sprayer with a focused spray right on the weed. Be careful not to get it on any plants you like, because vinegar isn't selective and will kill everything. I don't use it if it's really windy out because of the drift effect to other plants. I also have a friend who uses "horticultural" strength vinegar... she bought it at her local garden store. She said it's more potent and kills the weeds much faster than regular vinegar. I haven't tried that yet, but she swears by it. Good luck in your garden!