PsycInfo PsycINFO is the primary database of psychological literature, as well as related disciplines such as medicine, psychiatry, nursing, sociology, education, pharmacology, physiology, linguistics, and other areas. It indexes over 1800 journals, English language books and book chapters, dissertations and technical reports. Many articles include links to their full text.
Web of Science The Web of Science provides web-based access to both the Science Citation Index Expanded, covering over 5,300 journals, and the Social Sciences Citation Index, covering over 1,700 journals. You are able to perform traditional subject and author searches, and the reference lists for each work are included. You can also find out who has cited a particular work (Cited Reference Searching). These databases can be searched separately or simultaneously, and are updated weekly.
Google Scholar Enables you to search Google specifically for scholarly literature. Fast and easy resource, but remember that it is not comprehensive in any way and there are no summaries or abstracts. Especially useful for cited reference searching. Use the Advanced Search option for best results. Find out more about it here: Google Scholar Search Techniques
PubMed Index to medical literature, including many psychological aspects. Especially useful for clinical psychology, physiology, comparative psychology, and pharmacology.
MIT CogNet The database features works of cognitive neurosciences including journals, books, reference materials mainly by MIT Press.
Dissertations & Theses Identifies doctoral dissertations and masters theses, includes some international but mostly U.S and Canada; full text PDF files online for most doctoral dissertations and a very few masters theses
Annual Review of Psychology Critical literature reviews written by leading scientists; psychology is one of 41 disciplines for which reviews are available.
Academic Search Premier A multidisciplinary database which provides full-text for over 4,650 scholarly publications, more than 3,600 of them peer-reviewed. Includes topics in the social sciences, humanities, general science, education and most areas of academic study. Abstracts and indexing provided for 8,200 journals in the collection. Covers a wide range of academic subjects.