Hi Guys,
I have a simple question here. I have zoomed too far out from my tracks. I can see the entire 3 minute song on the space of about 4 inches of my screen. I try to zoom back in, but when I do, all that happens is that the wave-forms just get vertically taller. I am not really "zooming in" it seems... just making the tracks taller. How can I get back to the default view? 
 
Silly question, I am sure.
 
Thank you!

click the ALT+Z button to "Undo" zoom features.
this is basically a shortcut to go back to the previous view you have. its a huge time saver.
This might not help you now though if you have saved the project in this state.
 
to zoom vertically, hover your mouse on the timeline until it turns in to a mini magnifying glass.
then drag down or up to zoom vertical / or left right to zoom horizontal.
 
Hope this helps.

CTRL+arrow keys are my favorite. Left/right zoom out/in on the timeline and up/down on track height.