purina is one I personally don't like...very high in corn/sugar. check out
www.dogaware.com or
www.wholedogjournal.com.
canned food is less processed so better for puppy, and it's a myth that kibble keeps teeth clean so don't worry about that. if puppy is picky use the canned food and add some low sodium no MSG meat broth like beef broth or chicken. add bits of cooked yam or squash for a little something sweet since they like sweet things and this is healthy.
avoid supermarket kibble, generally it is not great but made mostly of grains or corn which is not very nutritious. Innova, EVO, Canidae, Wellness, are all very good kibbles and canned.
I do not rec beneful, purina, iams, eukanuba, science diet. read the labels. you don't want all that carby stuff.
info on the recall that killed thousands of dogs and cats
http://www.fda.gov/oc/opacom/hottopics/petfood.html
best of luck...u can also add cottage cheese, plain yogurt, cooked liver, all in very small amounts. you don't want too much calcium in particular and not too fatty as it can make them ill or be toxic.