How to protect your work surface...

Newspaper, cardboard, wax paper... all work well for protecting your work surface, but the thing I like best is cling wrap (saran wrap).  Our table has a heavy plastic cover on it, so the cling wrap sticks to it and stays nicely in place.  Just overlap several lengths of it, depending on how big of a project you're painting.  Clean up is easy too... just roll it off and the table is clean underneath.  Here's a picture... the paint is on the cling wrap, not the table cover!