I've never been audited but here's the website that I go by to claim things.

http://www.cra-arc.gc.ca/tx/bsnss/tp.../menu-eng.html

Almost anything for the home you can claim at least a portion of, and of course trips, groceries, toys, etc.

We just realized that we could claim light bulbs and furnace filters, never occurred to us, but it makes sense. It's the little things that you're so used to buying that you don't think to claim that you'll forget!