The result you get after dividing debt by equity is the percentage of the company that is indebted (or "leveraged"). The normal level of debt to equity has changed over time, and depends on both economic factors and society's general feeling towards credit. Generally, any company that has a debt to equity ratio of over 40 to 50% should be looked at more carefully to make sure there are no liquidity problems. If you find the company's working capital, and current / quick ratios drastically low, this is is a sign of serious financial weakness. - Excerpt from Investing Lesson 3.
You can find more information in the Financial Ratio subject.