fox82,
Well, when one lands, one needs to have the list of all goods/belongings they are bringing in and any to follow. This is a tedious process if one is bringing in a lot of stuff. One has to list things and attach values to what is being brought in. This list would include a car, if one is bringing a car. (In my case, I had already declared everything when I came in the first time with a work permit, so my process was slightly different. I still had to declare my car as "goods to follow" though, since I came in at an airport and the car was already in Canada and I needed to import it so it can stay permanently in Canada.) When you land, you would need the COPR, passport, and the list of goods (B4) which, if you will be bringing a car, needs the VIN number. After PPR, when you get your visa and COPR, the visa office should provide an explanation of what you need to know to land or links of where to find that information online. (i.e. Don't sign the COPR until you are actually landing and the officer tells you to sign it.) The actual permanent residence card comes in the mail in about 6 weeks or so, they said.
After landing, to get a SIN, one just needs to go to a Service Canada office with the COPR and passport. The process was easy and took me about 20 minutes. They gave me my SIN, and said the official card will come in the mail later.
One of the most important things to do is to register for health insurance coverage. I would do this on your first day as a PR, if you can. This process differs by province, so to find out how to do this, I would suggest calling your provincial health system in advance, so you are ready when the time comes. One probably needs the passport, COPR, proof of residency (electricity bill perhaps?), etc. I went in person to the local office to register. While there, they took my photo for my card (which was $8 in my province), and I will get my card in the mail, after the waiting period. (Quebec has a 3 month waiting period before the health coverage begins; not all provinces have a waiting period.)
Cars: If you have a car and are driving across a border to land, I think the car gets imported right then, at the border. Since I flew in, and had my car already in Canada, I had to go to the CBSA/customs office in my town with the form they gave me at the airport (listing my car), my passport, copy of my COPR, and VIN number and car model info (they wanted to know the date the car was manufactured, which is marked inside the car door). I imported it at customs and then will need to go in the next 45 days to get it checked for safety at the place they told me to take it, switch the plates to Canadian plates, get Canadian car insurance (and then stop my U.S. car insurance), and get a Canadian drivers license (which seems to be an easy switch, since I have a U.S. drivers license). There will be some fees/taxes to pay to do all this. So still a number of things to do in the next days/weeks...
I think that is about it. There are also some good, informative threads on here about landing (and landing by car), which might also be helpful as you look ahead to the next steps.
Good luck!