Searching Google: Domain searching
Search: politics art site:edu > will return results from educational websites - i.e. www.calarts.edu; www.ucla.edu; www.csun.edu; etc.
You can indicate any domain > site:gov (government); site:org (non-profit), etc.
Search: politics art filetype:pdf > will return only PDFs in your results
You can indicate any type of file
More Google search operators available here
Boolean Searching: AND, OR, NOT
AND - narrows your search: politics AND art > retrieves documents that include politics AND art; both terms in a documents for it to be retrieved.
OR - expands your search: politics OR government > retrieves documents that include EITHER politics OR government. Either term can appear in a document for it to be retrieved. Use OR when you are using synonyms in your search terms.
NOT - narrows your search (politics AND art AND california) NOT baja > will leave out documents that include references to Baja California
Truncation: Finds variant word endings
politic* > Retrieves: politics, politician, political
Keyword - this is the default search for many catalogs and databases
The record in its entirety (including the full text of an article in some cases) is being searched. This means each of the fields is being searched: title, author, contents/abstract, subject, etc.
Subject - Not as straight forwards as you may think...
The subjects of books are designated with Library of Congress Subject Headings (LCSH), which is "set" list of terms with strict rules about how terms are applied to items. If you use this field it is important to know exactly what the subject heading is. For example, if you are searching for info about the death penalty you will want to search with the term "capital punishment." Conducting a subject search on the "death penalty" will not yield any results.
Unless you are sure about the subject heading that is used, I recommend doing a keyword search first to help you discover what LCSH terms are used.
I often recommend to check out the advanced search forms in catalogs and databases. The more options you have, the more you are able to refine your search. This is a good thing. This is especially helpful if you are working with a student who is getting too many results.