Many of you are interested in e-learning and training issues as well as documentation and content management issues.
An excellent resource is the Online Learning Connection, an e-newsletter. A recent issue featured useful information about the differences among various online graphics and how well they compress into smaller file sizes.
They recommend using GIFs for screen captures rather than JPEGs because you lose too much information in the JPEGs. A newer format, called PNG (Portable Network Graphics or “ping”), is also good for screen captures.