Open Access means making research results freely (i.e. cost free) available to anyone with an internet connection.
Most articles are published in international scientific journals published by commerical publishers.
One route is called "the golden path," including Open Access journals.
The second route, the "green road", including self-archiving of already traditionally published articles in open institutional archives, like Pure, subject-based archives or their own websites.
Open Access journals have started as an alternative to the traditional magazine market and they are characterized by these and make the journal content freely available on the Internet and also allows the author retains the copyright to his article. The authors / institutions may pay an author fee to publish an article in these journals. Some OA journals cover their costs through membership fees and supported by research institutions.
Open Access journals peer (peer review) of the journal's scientific content in the same way as traditional journals.
The benefits for researchers are:
Open Access and predatory publishers: A Guide to Reviewing Open Access Journals
New open access journal published by the University of Borås
"Review of Open Acces Discourse (ROAD)
Eysenbach, Gunther. "Citation Advantage of Open Access Articles," PLoS Biology, 4 (5): e157, 2006. Available at http://dx.doi.org/10.1371/journal.pbio.0040157 (2007-10-22))))
Geist, Michael. "Push for Open Access to Research", BBC, February 28, 2007. Available at http://news.bbc.co.uk/2/hi/technology/6404429.stm (2007-10-22)
Sander Wall, Erik "Commentarium on Open Access to Research", 2006. Available at http://piex.publ.kth.se/coar (2007-10-22)
"The effect of open access and downloads (hit) on citation impact: a bibliography of studies", The Open Citation Project. Available at http://opcit.eprints.org/oacitation-biblio.html (2007-10-22)