Many OA journals do not charge fees, or will waive fees if the author is from a developing country or does not have funding. OA fees (APCs) are generally an acceptable expense in grants - so you can budget for them in your grant application.
If you do need to pay APCs there are some other sources of help in paying fees:
Publications Fund from Research Services: Up to $1500. See this page for more details.
Discounts for Article Processing Charges (APCs) by publisher:
RoMEO is a searchable database of publisher's policies regarding the self-archiving of journal articles online and in open access repositories. Most publishers will permit you to post a copy of your article but usually restrict this to certain versions of the article, and may require you to wait a certain number of months before you post (i.e. the "embargo" period). RoMEO will tell you the policies of your journal.
More and more funding agencies are requiring recipients of their grants to provide open access to their research results. Does your funding agency require OA of your outputs? Find out by searching JULIET!
The Directory of Open Access Journals (DOAJ) is a service that indexes high quality, peer reviewed open access research journals, periodicals and their articles' metadata. Journals must apply for inclusion in this quality controlled list. This is an excellent place to search for reputable open access journals in your discipline.
CARL Canadian Author Addendum & Guide (PDF) - This guide will take you through the steps to using the addendum form to modify the publication agreement in order to retain more rights to your published work. Link to the addendum is in the guide.
The Scholar's Copyright Addendum Engine will help you generate a PDF form that you can attach to a journal publisher's copyright agreement to ensure that you retain certain rights (you can select criteria).
You can also modify the publication agreement yourself to suit your unique requirements. See this list of the various rights that you may want to retain.
Grant recipients are required to ensure that any peer-reviewed journal publications arising from Agency-supported research are freely accessible within 12 months of publication. Recipients can do this through one of the following routes:
NSERC & SSHRC: This policy applies to all grants awarded May 1, 2015 and onward.
CIHR: This policy applies to all grants awarded January 1, 2008 and onward. CIHR grant recipients have additional responsibilities to make their research data publicly available (see the link above for more details).
Gold OA is publishing in an OA journal (or hybrid journal) and the article is immediately available OA. Sometimes there can be an article processing charge (APC) for this.
Green OA is publishing in a conventional journal and then self-archiving a copy in an open online repository. Often there can be an embargo on the article, so it is not immediately available OA.
There is now considerable evidence that open access articles are more highly cited. This is known as the OA Citation Advantage.