Portal with wide variety of categories; most useful are the evaluative and descriptive annotations for each entry, so you can see how the possible "consumer opinion," for example, sites vary. Place to find free reference tools.
basic concepts broken down into useful small steps, with many visual examples to guide process. Web 2.0 in that it provides for interaction and author's introduction to sections.
personal productivity, life hacks, and simple ways to make your life a little better; check out "classics"; good for grad students who need to organize gettting through and out earning a real living