Journal articles, magazines, and news in almost every subject area.
Spend some time brainstorming keywords and search terms. Use subject headings or descriptors to help generate search terms.
When you find a good article, look at its References or Works Cited list. That will often lead you to other useful sources.
In addition to searching the research databases listed here, you may also want to try searching in specific subject specific journals. Search Holy Cross' EJournal list here.
Examples of journals: