The Educational Resource Information Center, contains more than 2,200 digests along with references for additional information and citations and abstracts from over 1,000 educational and education-related journals. This database is also available via ProQuest
PubMed is a web interface that allows you to search MEDLINE, the National Library of Medicine's database of citations and abstracts for biomedical research articles. The core subject is medicine, but subject coverage also includes bioethics, biology, chemistry, dentistry, environmental health, genetics, gerontology, health care planning and administration, history of medicine, hospital administration, microbiology, nutrition, nursing (International Nursing Index), physiology, pre-clinical sciences, public health, sports medicine, veterinary medicine and zoology. MEDLINE covers over 4,800 journals published in the United States and 70 other countries. The database contains over 15 million citations dating back to 1950. Coverage is worldwide and updated weekly.
The content in MEDLINE and PubMed is the same - they use different interfaces to search the same data. See also Europe PubMed Central - while most content there is mirrored from the US PMC, there is unique content.
Google Scholar "provides a simple way to broadly search for scholarly literature. From one place, you can search across many disciplines and sources: peer-reviewed papers, theses, books, abstracts and articles, from academic publishers, professional societies, preprint repositories, universities and other scholarly organizations."