A good place to start is here:
http://www.dogfoodanalysis.com/dog_food_reviews/

Read some reviews. You will learn quite a lot!

Put Proseries and Nutro in the search and read their reviews, too.

I've found that most of th 6 star foods are for highly athletic dogs - dogs doing Agility, flyball, sled pullers, etc. They are high in protein. Too high for my lazy bones, who would sit in the sled and expect me to pull it! They were getting "protein itch."

Clover should be on a puppy formula until she is about 1 year old.