What you do not mention is the type of dry food you are feeding. Are you giving the dog a "premium" food such as Iams or Eukanuba? or is it a "grocery" brand such as Purina or Kibbles 'n' Bits? Carrie has the right of it, too, in that it is important for several reasons to teach the dog by taking up the food after 15-20 minutes. The reasons for this are: it teaches the dog to eat when the food is available; it reinforces the dog's place in the pack, i.e., you are the giver of food; it allows you to monitor the food intake and weight of the dog; and, if the dog is reluctant to eat his/her food, it could be a sign there's a health problem.
If it's not a problem for you, a little warm water is okay, but makes for a mess if you have to take the bowl up full. I would recommend a good premium food with a meat meal in the first three ingredients fed dry. I only ever use water on the food for very young puppies and have had no problems later in life. Good luck.