It's not a big deal as long as you realize you have another agency or couple of agencies to work with for crossing international borders.
#1 - Flight Plans - VFR/IFR whatever, you have to file a flight plan going cross border. On the way back to the US, the words ADCUS (as in Advise Customs) must be on the plan and you must go to an AOE (Airport of entry) either by doing so at the hours specified for the station or by paying the overtime for an officer to come meet you. IFR flight plans are simpler (in my opinion) than VFR. It helps to get a copy of the CFS (Canadian Flight Supplement) to get a handle on all the Canadian variations, but most intelligent pilots can work out the slight differences in a CA flight plan.
#2 - Customs and AOE - when crossing boundaries, you must land at an airport of entry. In Toronto, pick one - I like Toronto Centre (Island) airport or you can use Buttonville Muni - both have Canadian Customs. Using Pearson is kind of crazy when you got two nice reliever airports.
For Canadian Customs, my view has been if the airport is officially "open" then Customs is there. You will be "greeted" by the Customs folks who quite rightly may or may not ask to inspect your aircraft. Canadian people are known for being polite - hard to believe that the simple 5-6 mile distance across Lake Ontario can make the difference in polite. (Ala - wait till you come back to the US!)
You will have to pay a Customs fee to Transport Canada - it was pretty nominal, the last time I was there. You and all your passengers will have to fill out a Customs Declaration Card - the Canadian one has two sides, one in French, one in English. Fill out all the blanks. Having a passport is far easier than the birth certificate and Driver's license bit. After you get the Declaration Card, fill it out and hand the card and your passport back to the agent, pay the fee and you're in Canada.
Returning to the US is a little more trouble. ADCUS is not considered "reliable" in the US Customs view of the world. That is, they are at the end of a "telephone" game they don't want to lose. In the game, you tell Canada FSS to ADCUS, CFSS tells a US FSS that you are ADCUS and the Flight Service Station is supposed to Alert Customs that you are coming. If you read the rulebook, it is the pilot's (operators) responsibility to advise Customs x-number of hours prior to arrival. I still put ADCUS and then I call the Customs number at the Airport of Entry (all of these are listed in the front of your AOPA directory).
For me, I pick the first big airport I come to - for example from Toronto, I'm flying direct to Buffalo and checking in. Buffalo has one-hour notice and long hours for their Customs office. If you look at New Hampshire, you have to go to Portsmouth (with an on call charge) or Lebanon between 10am and 10pm but with 3-hour notice! The easier you make it on the Customs official the easier your entry will be.
For your first flight of the year, you will required to buy a $25 airplane decal - it hurts if you only cross the border once - but it is good for one year. You will fill out the forms at the customs office.
Again, you will have to fill out a Declaration Form for each passenger and if you did call out an officer from overtime or on-call, you will have to pay the appropriate charges. Again, Buffalo during normal business hours makes this a whole lot easier.
Once you have "cleared" Customs in either country you are free to fly around the country following their airspace rules. Be careful, Canadian rules are a little different.
#3 - A word about Noise Abatement in Canada - you are going to Toronto - they are really, really serious about Noise Abatement. If a procedure is listed (even in the AOPA directory) to avoid something, you better follow the rules or expect a "call the tower" notice. It amazing - you can land cross ways at Pearson, make two Airbusses divert and create all kinds of chaos and the tower will joke with you about needing to pay attention - but you turn early and wake up the Lions at the Toronto Zoo and they'll have the police waiting to arrest you!
The process is really simple if you are just doing the normal travel back and forth across the lake.
Paperwork:
Have your passport - it solves all problems.
Pilot's License and Medical - you'll get a dirty look about not having a Radiotelephone Operators Permit but the Canadians know that US GA pilots are not required to have one. (In Canada, they take a separate "radio test" to get theirs!)
Cash - pay cash to Customs
For the airplane - ARROW. Also, if this is not your airplane, make sure you have a notarized letter authorizing your use of the airplane to Canada. Do not fly the airplane on a pink slip - i.e. temporary registration - the airplane must have the white card.
Since Toronto is SARS capitol of the world now, you are required to fill out an extra yellow sheet that says you have not had a cold that would be considered SARS in the last 14 days. Just check the three boxes and get out of there. Customs has these forms too.
