My printer won't feed paper.

Not often mentioned, but a known issue with printers is using the cheapest paper on the market. This stuff will place paper dust in your rollers and reduce the life of your printer. In a way, it is like using talcum powder in the machine. Additionally, if there was ever a paper jam and someone forced paper out, you COULD have stripped the rollers.
If you are still in warranty, then you can have them replace the printer.
At a certain point, you have to weigh out the time into repairing it and the amount of cost to replace it.
This blog seems to be a worthy place for information on Canon printers:
http://canon-resetter-repair.blogspot.com/