if you do a search under dog food you will be able to pull up some great info on types of dog food. There are so many that its hard to name just one. Some foods would be ok for one dog but bad for another.
THe search button is on the top left part of the screen.
The best food is what works for your dog. Finding that best food is trial and error. If you are lucky enough to have a dog that does well on anything (I have 3 of those!) you shouldn't have much trouble. If you have one that has foody issues it can be tougher.
When looking for a quality food, one of the first ingredients should be a meat meal. Not just "chicken" or "lamb" but "chicken meal" or "lamb meal". I prefer single meat protein source foods. With the grains look for good quality ones such as brown rice, oats and barley. Avoid foods with wheat, soy and corns like the plague.
I don't remember where you are located. Is there a Petsmart or Petco near you? You might consider a Large Breed Puppy Food ... ProPlan (by Purina) is a better choice over the regular Puppy Chow. Also, if you don't have the above stores, you probably have a feed/seed store which should sell the ProPlan or possibly even Diamond Dog Food. It, too, is better nutritionally for your puppy. I would not free feed him; that will make him fat.