Going to Canada is no problem.
Returning home can be if you don't follow the rules. Check out the US Custom's website or call FSS. You will have to pay $25 for an airplane decal (since you are an infrequent flyer, this is easiest). The decal is good for one year. Find an Airport of Entry that you will use and pay strict attention to the hours of operation for the Customs service or you will have to pay the officer's overtime out of your wallet. (For example, just use someplace like Buffalo, NY where there is 24hr. service rather than someplace like Plattsburg, NY) If I remember the forms are #178 for declaring the Aircraft, #339 for the Decal and if you are going to make it a habit #442 for the GATE program. You must file a Flight Plan each way. In addition to putting "ADCUS" (Advise Customs) on the flight plan, I highly recommend that you get the number for the Customs Office you are going to visit and call them directly just before departing Canada. US Customs considers it the responsibility of the US Citizen to make contact about re-entering the country. Asking Transport Canada to do it for you in the form of their Flight Plan is considered a convenience. You can find info on AOPA, FAA or Customs web sites.
If you use ATC services in Canada, I do believe you are now billed for the priviledge.
