The last thing I had a problem with was using a BorderLayout manager....
I had been reading from Sun's website: http://java.sun.com/docs/books/tutorial/uiswing/layout/border.html
The page notes that: Because content panes use the BorderLayout class by default, the code does not need to set the layout manager.
In my case I found that it was NOT using BorderLayout until I explicity specified it.
Going back to my example.... My "Main" panel was a borderlayout. within the center panel of the borderlayout I was adding another panel that was boxlayout set to show components in rows. When I tried to add something to the "North" section and then the "Center" section of the outer Borderlayout.... it all appeared in a single row... (boxlayout format).
I ended up finding the issue in that I had to go back to the BorderLayout panel and specify that layout as borderlayout instead of relying on the fact that it would be set to that layout by default.
But my real question here is in regards to testing. I did not have a way to solve the problem other than by trial and error. Are there any testing tools that would have allowed me to gain some insight as to why the components were being placed as they were on the screen? As I progress, I would imagine that the GUI's that are produced could potentially get fairly complex. It would be nice to know up front if there is some simple method for debugging the results of this sort of thing.