What's in Windsor?
Passports work best as ID for crossing the border.
Don't bring a handgun. You will be asked if you have Alcohol, Tobacco or firearms or ammunition with you or in your vehicle.
Don't lie to the customs and border patrol folks. Answer only what you are asked, volunteer no extra information. Be honest about your past, the two countries share all kinds of information about its' citizens.
Have a specific destination and time frame for being in Canada when asked.
Fuel, food and accommodation will be more expensive but that will be offset by the currency exchange, your dollar is worth about 1.25 Canadian right now. Figure on 100$ per day for fuel and food + accommodation costs
Here is a neat round trip map for you.
Stage 1. https://goo.gl/maps/326CXnRhpUv
Stage 2. https://goo.gl/maps/XHpo1e643iS2
To add on to what he said (he is the most helpful Canadian I know).
Get an insurance certificate from your motorcycle insurance carrier. Mine was State Farm, and they wanted to know when I would be in Canada. Be broad, select more than your planned trip, just in case. Carry it with you.
Check your Health Insurance carrier to see if you are covered in Canada. Canada has Universal Health Care, but only for Canadians.
Be aware that most Harley speedometers do not have Kilometers Per Hour printed on them (dumb) like most cars do. Garman GPS systems that display the local speed limit will know what it is in Canada, and display it in MPH. Very handy. There is a simple formula you can use (google it) but just remember 100KPH is 60MPH.
Do try and follow the routes Calgaryglide listed. He gave me some really good ones for my last trip, but someone was trying to burn down British Columbia (entirely) so I had to adjust. Always be ready to adjust if you wander up north.
Petro Canada stations seem to always have Premium (91) and most seem to take American Credit Cards at the pump. Not all stations take American Cars at the pump. Some stations may fuck you over by requiring you to pre-pay a certain amount at the counter, then refund the difference when you are done. That is two foreign currency transactions. Fuck that... Others just want to hang on to your card while you pump and charge what you bought. They are vary picky about drive-away gas thieves.
Ice Field Parkway in Jasper National Park is awesome, beyond awesome. If you plan on visiting a bunch of National Parks, go to the Parks Canada web site and look into a park pass. Do that well in advance, they will mail you one so you don't have to deal with paying at the booth. As I recall, one pass may be good for more than 1 bike.
Canada is an awesome place to ride. The people are great, there is sooooo much beautiful scenery out west (Alberta and British Columbia). Saskatchewan is like Kansas, only bigger so watch your gas.