Making changes to a picture or part of a picture with Photoshop Elements 5 means making selections. Conveniently, Photoshop Elements 5 gives you a whole list of keyboard shortcuts to help you with every selection task:

To Do This . . . Do This . . .
Add to selection Shift-drag
Deselect from a selection Alt-drag
Deselect all but intersected area Shift+Alt-drag
Deselect Ctrl+D
Reselect last selection Ctrl+Shift+D
Select everything on current layer Ctrl+A
Hide selection outline Ctrl+H
Cut selection Ctrl+X
Copy selection Ctrl+C
Paste last cut or copied image Ctrl+V
Paste into a selection Ctrl+Shift+V
Adjust levels Ctrl+L
Adjust hue or saturation Ctrl+U
Adjust image size Ctrl+Alt+I
Open pop-up menu for Create options Ctrl+Alt+C