I’ve been exploring the darker areas of Sigma-Aldrich’s website lately, and I just wanted to highlight their technical bulletins.
A lot of them contain just what you’d expect, rather dry physical properties of chemicals and labware (ie. AL-223, Description of Pyrex Glass), but there are a few real gems. My picks, in numerical order:
**AL-134 Handling Air-Sensitive Reagents
AL-143 Mineral Adsorbents, Filter Agents, and Drying Agents (HTML)
AL-230 Pressure Conversion Chart (handy)
**AL-134 is a really nice intro to dry technique, filled with pretty pictures and all the rest.
 Have you seen their web toolbox? http://www.sigmaaldrich.com/technical-service-home/web-tool-box.html I could spend a good hour just reading up on different ways to give mice cancer. http://www.sigmaaldrich.com/life-science/cell-biology/cancer-research/learning-center/carcinogen-selector.html