An excellent read, describes a simple css methodology to help making your CSS work on most if not all modern browsers. here is the substance:

  1. validate your site (use w3 validators) to spot typos in your tags
  2. stay in standard mode (as opposed to quirks mode) by specifying a doc type (recommended: html4.0 strict)
  3. remove default styling of elements
  4. solve remaining browser bugs: useful resources

Read the article here: Friendly Bit » Cross-browser strategies for CSS