Linguistics and Language Behavior Abstracts: LLBA is the most comprehensive database and the only one devoted entirely to linguistics. Important: LLBA is not included in Multi-Search, so search it separately through its own interface.
MLA International Bibliography, 1926-present: The major source for locating scholarly articles and book chapters in literary criticism and language studies. The MLA DIrectory of Periodicals is also searchable through the top menu of this database.
JSTOR: A collection of full-text scholarly journals in the humanities, social sciences, and sciences. Coverage begins with the journal's first issue, and JSTOR's "rolling wall" means the past 3-5 years are usually not available.
Project Muse: Like JSTOR, Project Muse is a collection of full-text scholarly journals in literature, the humanities, and some social sciences.
Google Scholar: A free resource. It is worth checking your search results against what you find in the databases above.