Hi eallison88,
I will answer your questions :)
Healthcare: Healthcare (hospitals, drs visits etc) is free and good, there is a waiting period when you arrive which I think is 3 months, you will need private insurance for this time. Most jobs also offer extended healthcare (usually one person's will cover the entire family), which covers dental, prescriptions and other things such as eye tests/glasses, massage therapy, speech therapy, some of these extra things are capped at $500 per year.
Cost of living:
I would say high, some stuff is cheaper eg petrol (gas), cars, but then car insurance can be much higher, grocery costs are a little higher, utility bills can be very high in Eastern Canada. Housing costs are high near the major cities but cheaper elsewhere.
Religion:
I have live in West and Eastern Canada, and it is MUCH more religious on the East coast, here they have a big Catholic school system (kindergarten to grade 12) which you can choose to send your kids (great schools, no fees), and lots of Churches, they are very active from what I can tell. In Vancouver there are a handful of fee paying Catholic schools. I do not know about the rest of Canada.
Jobs: I am pretty sure there is a job list of occupations that are elligible for a working visa. Try googling Canada immigration.
Visa: You should apply for Permanent Residency, but a visa might be easier/quicker if you have the right job skills, you can then apply for permanent residency once you are here for 3 years.
Most of the information you need is on the web, you should visit britishexpats forum for lots of support and guidance.
hth (and good luck with your planning) :)