Please find a lot of resources at NCAP (Northwest Center for Alternative for Pesticides).
For those of you who might like a less toxic approach for dealing with weeds around your homes, we offer this recipe for an alternative to toxic products such as Roundup. Here is a recipe for a vinegar-based homemade herbicide. It works well on foliage, but does not kill all the roots, so things will re-sprout, but they often do, even when sprayed with toxic herbicides.
Homemade weed killer:
1 gallon of Vinegar
1 cup Epsom salts
1/4 cup Dawn liquid dish soap(the glycerin in the Dawn brand makes it work well. Other brands could work, too).
Mix above ingredients in a spray bottle. Spray weeds thoroughly. The Dawn dish soap strips the weed of its protective oils and helps the product stick to the plant, so the vinegar can work with deadly force. Safe for use in yards used by children and pets. Be careful where you apply it, as it will kill non-targeted plants, as well. It works best, if applied on a warm, dry day.
Flame-weeding is another way to kill weeds. It is often done with a propane-powered torch that is made for that purpose. It works best in areas removed from flammable materials (such as sidewalk or driveway cracks, gravel walkways, etc). Use torching or flame-weeding with caution in dry season and around any flammable materials.
Some people use steam or boiling water. This has to be done carefully and safely.
Cutting weeds short and covering them with thick layer of mulch or dark light-blocking landscape fabric for a period of time can also work.
Or dig them out.