SPARC Open Access Fact Sheet - This 2-page fact sheet from the Scholarly Publishing and Academic Resources Coalition (SPARC) provides basic information about open access. SPARC is a global member organization working to promote open information.
Peter Suber's Open Access Overview - This brief but thorough description of open access provides an accessible orientation for those new to open access.
Budapest Open Access Initiative - The Budapest Open Access Initiative defined Open Access for the first time in 2002. Since then the organization continues to survey the scholarly community and release updated recommendations.