You can buy them from apple for the ibooks app. There are also apps that let you buy books from Kobo, sony, and amazon. I'm Canadian too, and i find apple's ibook prices higher than kobo and amazon - i haven't purchased from Sony for a long time, so can't comment.
You can also borrow books from the library to read on your kobo app. Also there are a lot of free books - such as here at mobileread - but they are older books in the public domain, and you said you wanted contemporary. I'm not up on fan fiction, and other similar types of fiction, but i think believe there are sites where you can read those for free as welll.
Good luck with your ipad.