What about dog food!

I get so confused when I read the labels on dog foods.
With dogs eating their own feces and cat poop, what is all the hype about?
I really get annoyed when I look outdoors and see my puppy, Maggie eating her feces! I buy a premium food and am always looking to improve that.
I even bought a subscription to The Whole Dog Journal so I could get their information about good and best dog foods.
I had been buying Iam's at first and then saw they had ingredients in there that were not that great. Then I tried Beneful just for different type of food and they say that there isn't anything good in there.
What is a dog owner to do?
I finally settled for Foster's and Smith's senior food for my older dogs and am having it sent for six months as a trial. Who knows? I just want the best for them, and sometimes wonder if the big companies even put the stuff in there that they say.
I was also wondering with all the people in different jobs, why no one ever comes across anyone who works in the places that make them to ask from the horses mouth?
Anyone have any suggestions or success stories from fooods they have tried?
With puppies and dogs getting up there in age, I want to have them around for a long time.
One web page even suggested that dogs can live as long as 30 years on a good diet. I find that extremely optimistic!