I'm thinking about taking one of the online Athabasca courses, can anyone suggest one that is pretty easy/that won't take up too much of my time?

Regular University courseload + an online Athabasca course seems like overload to me. Don't want to overwork yourself and get really stressed out.

Why an Athabasca course? I haven't heard much about Athabasca, are their courses credible and good? I'm always weary of online universities.

Athabasca is a legitimate, accredited distance education university. Their courses are decent. You do need to make sure that the course will transfer to McMaster just as you would with any other university.

As far as choosing an easy course... that depends a lot on your interests and background. As somebody who is generally terrible at math with no background in science, I would find a course that required either of those difficult. On the other hand, if you struggle to write papers or read quickly you probably don't want to take an English course.