Because it's come up a few times in comments to Becoming an Editor and in conversation, I'm putting this disclaimer in a separate post.
The question in question is some variant on "Should I go to Ryerson or George Brown?"*
The answer is "I don't know."
The Certificate in Publishing is offered through Continuing Studies at Ryerson University. It's a comprehensive look at publishing in Canada, with a discernable bias towards trade- and scholarly book publishing. I took several courses there, and I know several of the instructors—they're all professionals I hold in high esteem.
The Certificate in Editing at George Brown College offered through the Continuing Education at George Brown, and focuses on as many different fields and media as the instructors can manage. It is less book-focused, and does not offer courses in publishing per se. I am one of the instructors there, at the moment (full disclosure!), and I have nothing ill to say of my colleagues.
Because I really do respect and esteem people who teach in both programs, I'm not going to say much more about either of them.
In Toronto, Centennial College and Humber College also offer programs in publishing. I know editors who have attended Centennial and the only reason I don't often recommend the Centennial program is that it is a full-time program, and most of the people I meet are not in a position to attend school full-time. I don't know anyone who has attended Humber, so I really can't say much about the program there at all.
Which program is right for you depends on your goals, timeline, budget, circumstances, and personality. I suggest you take the time to compare the calendars and attend the information sessions for each program, talk with instructors about the program of study, and make your own decision. Do bear in mind that there is no one single path to a career in the field, and that there is no clear path from wherever you are now to the career you want. Keep taking steps to get yourself closer to whatever your goal is, keep improving your skills, keep learning about the industry, and accept that certain paths are narrower and rockier than others.
*If you're not living in Toronto, then you can't take editing at George Brown College, and I have even less experience of editing courses and programs offered outside of Toronto.