Academic Search Complete is a good general starting point for articles. It contains many peer reviewed sources. You can restrict searches to retrieve only articles that have been approved for publication by a panel of experts.
Librarians recommend that juniors, seniors, and graduate students who are:
biology majors consider BioOne for environmental science, and the many open source peer reviewed journal services listed on the research guide for Biology,
Sources for data and statistics vary by subject area. Ask a reference librarian for sources of data on your topic, or click on "Statistics" links in science and social science subject research guides.
Professors may encourage you to consult primary sources, such as historical documents or unpublished manuscripts. The Averett Library archives contain primary source materials on regional history. Librarians at the reference desk can help you locate reproductions of primary source documents, many of which are available in digital libraries.
Averett librarians recommend that you save time and effort by recording citations and notes for the most helpful sources as you discover them. See annotated bibliography for details.
2. If your professor approves, include authoritative web sources (for example, from Google Scholar@Averett or Google). Cite web sources only if:
author name and affiliation are displayed
the information is accurate and conclusions are supported
the author acknowledges the research and ideas of others
the information addresses one or more aspects of your topic
the web site does not indicate political or social bias (unless, of course, you are studying media bias)
you have gathered a variety of sources (books, articles, data or statistics, and web sites)
3. Focus your topic, create an outline of your narrative, and select from your annotated bibliography, representative sources supporting your thesis: your ideas and perspective on the topic.
Take care to cite all of sources quoted or supporting your narrative. This will allow your readers to consult the same books, articles, and web documents you used. For more information, see Annotated Bibliography, MLA Citation Style, and APA Citation Style.