Google Books Search allows to weigh the most important research. In most cases, you can look inside books, and see how certain sources are cited. This gives a very good idea of how important a certain sources is in the field.
Google Scholar is just so fast, and has so many additional features that it beats a regular database search for the purposes of the initial lit research. Its shortcoming - very few full texts are offered. Therefore, one may resort to looking for sources on Google Scholar, and then retrieving full texts through a library database.
Google algorithm is also better than most database searches. If you start without quotation marks, the initial results maybe exactly what you need. Although most likely, they won't be.
Google Scholar also gives a citation index, which is very useful in determining the importance of older papers; it may not do much for newer research.
Go to Advanced Scholar Search, and enter your university's library. It will help you to find a full text in your own library.
You can set preferences in Google Scholar which allow you to export a reference to EndNote or any other formatting software.
PsycINFO - Excellent source for articles dealing with learning, cognition, and anxiety related to specific subjects or use of technology. Methodology limit permits limiting search results to quantitative study, qualitative study, literature review, and meta analysis, among the many options available. Age limit permits finding research for a particular age group without the need for additional terms in the search.
ERIC - Publication type limit permits limiting search results to just research articles and documents by selecting "reports: research." Also use educational level limit rather than terms to search for elementary, middle school, high school, post secondary or specific grades. Do not check Peer Reviewed unless you only want articles from 2003- as that is when ERIC started using this designation. There is no direct way to find literature review articles in ERIC so need to use ProQuest Education Journals (the best!) and Professional Development Collection to do that for the education literature. In ProQuest, reveal More Search Options and use the Document Type limit to select literature review. In Professional Development Collection use the Document Type limit to select literature review.
Social Sciences Citation Index - While literature review articles provide a history of research on a topic, this database takes the research forward by showing you articles that are citing a particular study or significant researcher in their research. Use Cited Reference search.
WorldCat - use to find what books and dissertations are available on your topic worldwide.
ProQuest Dissertations & Theses - online version of Dissertation Abstracts provides abstracts for dissertations.
Full text scholarly journal providers are good places to search - Sage Full-Text Collections contains American Educational Research Association publications - American Educational Research Journal, Educational Researcher, Review of Educational Research. JSTOR provides full text from the first issue through 1-5 years ago of core education journals like Child Development, Cognition and Instruction, Elementary School Journal, and Peabody Journal of Education.
If you're not sure what a phenomenon is called, try description of a practical situation; sometimes that will lead to a proper research. For example, "refusal to read" search will bring a number of papers on reading difficulties linked with attitude or resistance, rather than with various inabilities to read.