I think most of the info you need will be US requirements since you will want to insure and plate vehicle in order to drive it back. This site will give you our Ontario resident requirements:
http://www.mto.gov.on.ca/english/dandv/vehicle/used.htm
Not being a resident you will not of course be able to register a vehicle as either fit or unfit, nor will you be able to get trip permit.
If your state has safety and emission test requirements they may not be able to be done here since normally the testers have to be locally licenced.
Alternate is of course to have unlicenced car transported to your state. A neighbour of mine recently shipped a car to Oregon and had one shipped from California. If you wish I can get the name of the car carrier he used.
p.s. Here is our Federal government requirements re importing, I'm sure USA will have something less stringent.
http://www.ccra-adrc.gc.ca/E/pub/cp/rc4140/rc4140-e.html
