Organic weed control? That is a toughie. I suggest organic fertilizer. Include corn gluten meal as a pre-emergent for weedy grasses.
For broadleaf weeds it is more difficult--but think about the high iron products like Fiesta--and whatever else you can find.
Killing big brown spots using vinegar may not suit most customers.
For broadleaves you may wish to use carfentrazone (Quicksilver)--its about a hundred times safer than Weed-B-Gone...furthermore if you use it as a spot spray...you reduce the amount of chemical per acre to about 20 times less, (because you are only spraying the spots.) No odor and you don't need much--about a teaspoon per gallon.