Here's an interesting article about strategies for organizing data. As to eDiscovery issues, the author recommends classifying data in a few simple categories (e.g., "Regulated record," "Historical business record," and "Temporary nonrecord") to help with data retention, since "enterprisewide records retention are often stymied by their employees’ inability to understand all of the different categories and retention periods their records may be subject to."
(Source: http://www.computerworld.com/action/article.do?command=viewArticleBasic&articleId=9014071.)
