When you land in Canada, you will get the COPR ( confirmation of PR) signed, and with that you can obtain a SIN and register for healthcare ( even if it will not start right away). The PR card comes a bit later - currently it takes about 55 days to get the PR card sent to your address ( you indicate an address when you land). You don't need to wait for the card if you need to travel right away... you can exit Canada without the PR card, but you will need it to re-enter. If you get it sent to a friend for example, he can receive your PR card (it comes with normal post, no signature required), and then send it to you (be aware that Canada Post normally is not allowed to send a PR card outside of Canada, but if it's not obvious, then it should not be a problem).
Your wife is a citizen, so she can move again, without problem. For you, you need to spend 730 days out of 5 years to maintain your PR status. BUT - if you are outside of Canada with your sponsor (your wife), then the days outside of Canada will count in the 730 days, so if you stay with your wife outside of the country, you will be able to maintain your PR. However, the days spent outside of Canada can not count for citizenship.
So to take a concrete example: if you land on the 1st of January 2014, and then your wife gets a job in Japan(just an example). If you go and live with her in Japan from the 2nd of January, you can stay with her as long as you want, as the day spent with your Canadian sponsor count for the PR - so you are not at risk to loose your PR. After 55 days, the PR card arrives at the address in Canada, and somebody can then send it to you.
If after 3 years, you and your wife decide to go back to Canada, it's not a problem - you are still a PR, and you can enter Canada. If you enter Canada on the 1st of January 2017, from that date you need to be physically present in Canada for 3 years before you can apply for citizenship. Once you apply, there is a waiting period ( you get sent a book to study, then there is an exam, and in some provinces it can take a really long time - like a year - to get a date for the exam.).
What you can not do is: stay outside of Canada without your wife for more than 2 years out of 5, as you risk loosing your status. AS long as you are outside of Canada with your wife, as she is a citizen, the days spent together will be counted to maintain your PR status.
Good luck,
Sweden