Good introduction by Dan Cederholm.
Handy (albeit perhaps overreaching and not entirely the most semantic solution in the world) templates for a 960 pixel grid. Most useful: Sketch sheet templates to print out.
Easy little CSS library to use when you want to include diagrams of keyboard commands on an HTML page. Like, “Then, press Cmd+Shift+S to Save As a .png”
A casual guide to getting started in infographics from a seasoned veteran of major newspapers.
No nonsense tool to convert color codes.
A brief treatise in support of prettiness. More importantly, coherent example on why prettiness might matter. (We’re talking about design here.)
CSS charts and graphs.