[Landshark]

here's a quick n' easy......
open the background photo,
open the photo with the piece to be 'cut',
use either the magic wand/lasso/etc. to select your piece,
'cut' it out (the little scissors icon),
remove the remaining picture (red X in the upper right corner),
hit 'paste' (little clipboard icon),
click the 'move tool' (little arrow with crosshairs below it),
drag the corners until its the right size an move it where you want it

if you want to post the pics with instructions as to what you want, i'd be glad to do it for you. hope that helps,