The rule of thumb is to not feed anything that you can buy from Walmart or the grocery store....that means that Beneful is not a good choice either. Go to your local pet store and there are MUCH MUCH better choices there. Try Nutro or Merricks or something like that. In my opinion, the food "Canidae" is the best dog food on the market. Go to their website and you can find retailers in your area that will carry this food. Here's the "store locator" portion of their site:
http://www.canidae.com/company/storelocator.html
Here's their site:
http://www.canidae.com/dogs/all_life_stages/dry.html