Most printed products sold at retail establishments that scan items at the POS or checkout require a barcode. The book barcode usually comprises a graphical representation of the 13-digit ISBN (or Bookland EAN) and a 'price add-on'. BookNet Canada does not issue barcodes, but your printer should be able to help, or you can look for barcode providers on the internet.
NOTE: In the price add-on for the EAN barcode, the leading digit of 6 is used to signify prices in Canadian currency within Canadian trade publishing. The '6' prefix for the price add-on is reserved for Canadian prices. However, it isn't widely used in the Canadian market. You may want to check with some of your retail trading partners to see if they are scanning the price add-on and if they can scan a '6' prefixed price add-on.
There is a lot more information on barcoding in the BISG document Bar Coding Guidelines for the US Book Industry. We recommend checking it out to find out more.