Maintained by the National Library of Medicine, PubMed is a free web-accessible database that is comprised of more than 23 million citations for biomedical literature from MEDLINE, life science journals, and online books. Citations may include links to full-text content from PubMed Central and publisher web sites.
Important Note: The link above only takes you to the free edition of Pubmed maintained by the National Library of Medicine, which provides limited full-text articles. Accessing Medline through the library's subscription database Ebscohost will allow you to search the same collection, but will provide full-text to significantly more (not all) full-text articles.
For articles that you cannot get full-text through PubMed or MEDLINE, you can always request them through Sacred Heart University's InterlIbrary Loan.