Alan
It sounds like you are just starting out in Photoshop. There is a ton of information and tutorials on the Web that is available for free. To start, I recommend you check out the video tutorials on Russell Brown's site - in particular the tutorial titled "The Day With No Sky (Part Two)". Here is the link:
Alan
So how do I get the second image to appear on the same workspace?
Window > Arrange > Float all, then drag them around. (Or cascade)
There is also a preference setting that will cause images opened using File-Open to come up in 'windowed' not tabbed format. There is a small 'gotchya' with dragging and dropping image files on the PS CS4 workspace but that is the subject of another thread...
Michael
Alan