What can you do with a minor, really? What's the point of it? I was thinking of minoring in Biology. Can you minor in more than one thing?

Well, normally you complete 120 units over your four years at McMaster. A minor consists of 24 units in a different subject from your major. They're useful in a way such that you either use it to supplement your knowledge and future in the subject of your major, or simply as a way to raise your GPA if it's something you do well in.

Double minors are kind of difficult to pull off, seeing as that would be 48 units. Some programs don't allow this, some programs don't allow minors at all.

Double majors are possible depending on the program though.

A minor is nice to have if you have interests in a particular subject outside of your degree. Also, even though it isn't officially recorded on your degree, it's always good to be a more well-rounded person and looks good when applying to grad school and such.