Photoshop :: Crop Outside Image Once Inserted Onto Another Canvas?

So I have an image which I have moved onto another canvas I of course know how to transform an image, but how can I crop the image Ive just moved? So lets say I have a photo of a man that is too big for the new canvas. OK I can use transform to resize it (holding down shift to keep it the same constraints), but then lets say he is still too tall. I dont want to stretch it down in size as he'd look like a midget, so I decide I only want to use the torso and head.

I would have thought I would have used the marquee tool to draw around it, Select>Inverse>Delete key

and this would delete whats outside the marquee box (his legs etc). But that doesnt work. Crop is of course of of the question as it then crops everything on the canvas.

Yes, I COULD resize it completely first, but I'd rather resize/crop it once its on the new canvas.