Open Access is research that has been distributed online, free of cost or other barriers.
Why would I want to publish my work open access? As discussed on the Scholarly Publishing page, most journals own the rights to the articles they have published. This means that anyone who would like to read the article must pay money to do so. In addition, institutions (such as the library) must pay licensing fees to get access to these articles for staff and students. Publishing your work open access means that other researchers can find your work more easily, students will have access to the research, and individuals outside of the academy can view the research.
For more information about Open Access read about it here
If you are the recipient of a Tri-Agency Grant - the Canadian Institutes of Health Research (CIHR), the Natural Sciences and Engineering Research Council of Canada (NSERC), and the Social Sciences and Humanities Research Council of Canada (SSHRC) - you are required to make your research freely and publicly accessible within 12 months of initial publication. One way to ensure this requirement is met is publishing in an open access journal.
Other grants also may have their own requirements regarding making research publicly available.
Predatory publishing refers to exploitative publishers that usually require authors to pay expensive fees to get their research published. Generally, these publishers do not provide the same editorial or publishing services that reputable journals offer.
A librarian can assist you if you are unsure of the quality of a particular journal you would like to submit your work to, however there are a few you can think about to make these judgments yourself:
More tips can be found here
Directory of Open Access Journals (DOAJ)
DOAJ is an online directory that indexes and provides access to quality open access, peer-reviewed journals. DOAJ lists potentially all open access journal and provides metadata for harvesting.