2) Use articles from peer-reviewed journals (see the Evaluating Your Sources tab, above) and books from scholarly (mostly university) presses as much as possible to support your arguments. Some topics just won't work within these limits, but you can usually find and relate some scholarly theory papers to just about any topic with a broader view.
3) Use reliable databases to find reliable citations. Use your critical thinking skills and also use evaluation tools such as Ulrich's Periodical Directory when finding citations from unfamiliar sources. (Ulrich's Periodical Directory is also linked from the full-text locator tool Journal Finder.)
4) Find the invisible college for your topic-- the cluster of scholars most frequently cited and researching on topics related to your topic. When you are reading books and articles, make a note of the names of authors and research that often gets mentioned in different books and articles. This is the invisible college. Sometimes, ariticles in scholarly subject encyclopedias can help with getting some names, since the point of these articles is to make you aware of the most prominent research and scholars on a topic. Research Handbooks and Annual Reviews Online can sometimes help identify the key papers and authors as well..
5) Get in the habit of chasing citations-- following citations backwards and forwards in time-- who cited what and who cited an article. Web of Science is the best tool for this when it work for a topic. Google Scholar works ok if you are aware of the way results are shaped and what kinds of sources it covers. For example, Julia Ericksen "With enough cases 1998" and Eric Bourguet "Fluorescence Detection of Surface-Bound Intermediates 2004"
Exercise: tracing Dunning-Kruger effect back to source and forward to latest uses