It's well known to contain mistakes - almost every flight school knows it, hence the phrase ask anyone. I found it to be completely unsuitable when I took my Canadian exams, which is why I wrote my own (theirs went in the bin). Guy's Ballot's law is just one (very basic) example. It should be Buy's Ballot's law.
Anyhow, much of what you need will be in the AIM and the IR publications from TC.
There are free questions at
www.rtfq.org