There are several excellent meta-sites for sociology. These sites provide links to institutions and academic departments, sources of biographical and theoretical information, survey and statistical resources and much more.
Wikipedia can be a helpful place to start your research and get a quick overview of a topic. While it's a good place to get started, it is almost never listed as a reference and you should always check the citations. Watch to see that an article is well-documented and follow the adage "trust but verify." The American Sociological Association and the American Psychological Association have projects to improve articles in their disciplines.
Use Google Books for digitized books from major publishers and universities. Only those out of copyright (about 75 years old or more) are fully accessible; others are only partially accessible but often you can see enough to get real information or at least determine whether you want to request the a copy of the book through the library.
When searching for research studies that use a specific type of design or method, like quantitative, qualitative or quasi-experimental, you can have a more efficient and effective search by using some of the tips below to find these sources.
In some databases, you can search by methodology. For example, PsycINFO provides methodology as a limiter in their advanced search section:
For more details on PsycINFO, view this short tutorial.
If the database that you use does not have this option, you can enter the methodology that you are looking for as a keyword in your search. For example, if you are looking for experimental designs on the topic youth depression, you can enter search terms: "youth depression" AND "experimental design".
Note: Using quotation marks will search that exact phrase. However, you can also search without quotation marks. A phrase search (with quotations) will search that exact phrase and will narrow your search results. A good practice is to do multiple searches - modify your terms, find similar terms, do a search without quotation marks and do one with quotation marks (phrase searching).