How do you delete a photo from a canon powershot camera?

First of all, It depends on the model of your Canon Powershot camera. On a powershot A530, you simply press the upper left circle (on the back of your camera, then it asks you if you are sure you want to erase, or if you should decide not to, and to answer erase, use the left cursor on the big circle, and hit the button inside the big wheel (set) then that picture is erased. Hope I asnwered your question!