What does it take to create a simple icon? Read “Anatomy of an Icon” by Dan Cederholm (SimpleBits):

Great improvement in Help usability. According to HTML Help 1.4 SDK Longhorn Help will have task-based organization: Traditional Help content typically focuses on application features. The main difficulty with the traditional approach is that users often know what they want to do, but are not sure which feature to use. “Longhorn” Help switches the focus [...]

Windows XP Visual Guidelines is a must read for anyone developing applications for Windows XP.