After you return to Canada, visit Service Canada, probably both of you, and ask if your SIN's are still active because after 5 years of inactivity they may be blocked. You would have to fill out some form and show ID to get them unblocked if this was the case.
You can follow the steps here: http://www.cic.gc.ca/english/information/pr-card/apply-first-pr-card.asp to apply for a PR card. If you have been living with your Canadian spouse for at least 730 days in the past 5 years, you are eligible. You may have to provide proof of living together, tax records, shared utility bills to your US address or something like that.
It currently takes 152 days to get a PR card, see http://www.cic.gc.ca/english/information/times/perm-card.asp but you can arrange many things with your landing papers. However, although the PR card was originally only meant for travel, it has become common that various parties in Canada are asking to see one as a proof of your valid PR status. However, there is no law that says you must have one.