A couple of weeks ago, I wrote about the format that is best for printed material.

MarketingSherpa released an updated posting about what works best for electronic media.  The posting is based upon a reply from one of their readers about a great source for research done on this topic.

The Wichita State University Software Usability Research Laboratory has done several studies on the best typeface to use for electronic media.

The outcome - Readers read Times Roman almost as fast as Sans Serif (Arial).  So you can choose.