I like to use Scotts Turf builder with weed control or Scotts turf builder with haults for crabgrass. I use which ever one I'm having troubles with. Its a grandular, that you can put in a spreader. Really easy to apply, and very effective. Just becareful around your ponds, and if you have pets don't let them on it for 24 or 48 hours. Can't remember what the bag says.
They have different ones for each season, normally one application each spring for weedcontrol works.
The one with the weed control is very effective on dandelions, and you could accidently over spread into the neighbors and have a nice lush green, non dandelions section on up to your yard.
It also, makes your yard thick and green. I really like using the stuff. This year, I used the Scotts with haults for crab grass and just used a liquid weed b gone, for the other. That way I could space out the two processes.
Advantage to grandular vs. liquid is there is not measuring. Sure, you can over spread one area, but if you follow directions you'll be fine. Also, if there is a breeze in the air the mist from the liquid can travel, the grandulars don't.
Here's what I did this year. My neighbor has a corner lot, and he cuts the grass next day, here are those fuzzy dandelions in bloom. Well, when the wind or person blows them that is bunches of seeds and that travels to other yards. So, this year I talked him into using the one with weed control, he didn't realize that it was also a fertlizer. But, I tell you his yard has never looked better. Its also effective on clover, I always try to keep that at bay because bee's love it and I have kids that like playing in the yard. Don't get me wrong, I don't mind bee's, they can have all my flowers in my yard, just don't want one of my kids stepping on them barefooted in the yard.
Kim