Jon - as suggested call the registry office or alberta govt website.
The plates in alberta stay with the previous owner. You should be able to get an 'in transit' sticker. I think, but may be wrong, that you need to get a sticker for each province you are crossing.
Signing over the pink slip works in alberta, bill of sale is better and you can get one off alberta govt website. This only matters at your end though when you go to register in ontario.
And remember, For every solid western car you take east, you must take back 2 eastern cars with you
