I use the story of two houses to teach the names of the white keys. There is the big house of the three black keys and the little house, which is the dog house. As we learn more keys we find out that the big house is Grandma's house (G) and she loves to make things with apples (A). The F and B are the front door and the back door. Beside the dog lives a Cat (C) and Elephant (E).
Here are some worksheets I use to introduce the concept.
Google Doc Link: Name of the White Keys Worksheet
Name of the White Keys