Don't forget a car insurance rider for Canadian coverage. We just got back from a trip to Canada, had a wonderful time, and found each border crossing quick and easy. We were also prepared with printed lists of any item that resembled a restricted item or food, but were not asked. Have the documents ready to hand over along with your passports before you arrive at the Port of Entry.
One thing to remember when you get there is they drive at Kilometers per hour, and slower than we do in the US, so I recommend practicing reading your speedometer in KPH. Some newer cars have the ability to switch the gauges to metric. If you can it really helps. Have a great visit.