Silly question cuz its one of the 1st things you should learn in PS, but whatever, we are all n00bs at one time or another.
Use the selection tool, (try the polygonal 'lasso' one), and just trace an outline over whatever you want to cut out. Try a full outline to where you started the outline. Once you complete the trace, the area you outlined should be selected. You go boy. Now select the move tool (should be the black arrow on the top right of the tool bar, in PS7). Now using that just grab the shit you outlined, and drag it into a new file or wherever you wanted to put it.
If you plan on doing a lot of this tracing shit, I suggest getting a LOgitech trackball marble mouse. It makes tracing incredibly easy, as opposed to a standard-type mouse where if you are tracing a lot of shit and picking up and moving the mouse to reposition your trace , can fuck shit up.
