How do you layer images on Photoshop? Like, put one on top of the other?

No, apparently I worded it wrong. I mean, how do you put an image on top of another image? I've tried, but I can't figure it out.

have the first image in one layer
then copy the second image
make a new layer
and paste the picture. ( edit>>paste (i think) or CTRL V)

It won't let me copy it . . .

with photoshop to copy
you have to select all first (use the marquee too or go to select>>all) then go to CTRL C then go to the other image .. and hit CTRLV

CTRL+A to select all then CTRL+C to copy and then paste it onto the other image: CTRL+V

Thanks, that worked. But, whenever I paste the first picture, it comes out in the middle of the second one. How do I position it?

EDIT: Nevermind, I figured it out.