I know this topic is old, but I just read through it and it seems the Canadian system has not been explained.
Actually, I'm not even sure if this is representative of all of Canada, but at least for Southern Ontario:
There are two main school systems, about of equal size, each going from juniour kindergarten to grade 12. The public school board, and the (Roman) Catholic school board. I'm not positive about funding, but I believe both are government (tax) funded and operated, and parents can just choose to place their children in either option.
The public school board works very similar to the public school in USA (I think?). No religious study of any kind, with possible option of a world religion class in high-school.
The Catholic school board (what I went through) contains a mandatory Catholic-religion class every year. All grade 2 students go through the Catholic sacrament of First Communion and all grade 8 students go through the Catholic sacrament of Confirmation (although I don't think either are strictly mandatory). In grade 12, a World Religions class is available as well as the Catholic-religion class and students can choose either one as their mandatory religion class for that year. Almost all students choose the World Religion class simply because they've already had 11 years of Catholic-religion class at this point. The World Religion class I took was very good at giving a base for many different religions. I found no Catholic bias there, or in any science classes. Although that may just be from the specific teachers I was lucky enough to have.
Most Catholic schools (especially the high-schools) have a small chapel built right into them, room for about 10-20 people. And school-wide Catholic Mass is held during school hours for important Catholic dates (Easter, Christmas...), usually in the gym or even nearby church.
College and Universities do not give either school system priority (as far as I'm aware). And both offer plenty of world-wide religious courses.
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