haha, alright, where all your tools are, its the one that looks kinda like a sun with a stick going into it, and its in the right column 2 down from the top
on the tool palette it should be there, like a wand if its not, you press and hold on the icons and more selection come out of them, just try that on every one, cause i dot know what version you have
well idk about u but i downloaded photoshop off the internet, and i got photoshop and also imageready came with it, imageready is like i thinkkkk for animation shit like that, if u need a link for photoshop for a mac, just pm me
aright if your in CS, it should be on teh right column of the tool bar, 2nd down. slice is the third down on the right i think. the short cut is command (little clover gig) W, at least if its on a mac, which ill assume you are. if not it should be control W.