A "comprehensive directory of online philosophical articles and books by academic philosophers." A great research tool. Oh, check out their survey of what professional philosophers think about this and that.
Joe Lau's informal logic and critical thinking resources at Hong Kong University (also available in Chinese). Includes a free Miniguide to Critical Thinking. But watch out - I spotted one mistake on my initial perusal - you must engage your critical brain even when you are being told about critical thinking.
An extensive list of formal and informal mistakes of reasoning. Dip in from time to time to build your defenses against such errors. There's also a link to a list of common misconceptions; providing at least another half hour of top quality procrastination.