The anatomy of beautiful HTML. Covers all the guidelines and concepts that add up to good HTML coding.
#diagram
WordPress Stack
Handy diagram by Andy, showing the stack of includes/defines etc that power most of WP.
Google Chart API – Google Code
Google Chart API – Google Code
Surprisingly thorough charting API from Google. Intended to be accessed via JavaScript. Loads of style, color, shading etc options. No sparklines.
Rapid Application Development: An Entity Relationship Diagram Example
Rapid Application Development: An Entity Relationship Diagram Example
Good details on all of the elements available in ER Diagrams