Track folders are only available to see in Sonar's Track View which is the main screen that Sonar opens up to by default.

Wow... All I can say you guys rock!!! 
I can't thank you ALL enough!
Though I have yet to try out making folders , I feel like I totally get it now!
I'm just starting out trying to use a "real DAW" and some of the examples given are well, over my head to say the least.
I come from multi-tracking on a Roland MV-8800 (similar to a MPC-4000). 
I haven't made a proper MIDI track yet. All my tracks (so far) are Audio or VST Plugin instrument tracks.
I guess I'll start a new thread about MIDI tracks next, lol.
Thanks again everyone!

I remember feeling like folders was a huge step forward when they were introduced. Cleaned up the workflow greatly. A few cool tips: Expanding the "folder" section that contains the various audio tracks enables you to leave notes and text about any of the items in the folder...and you have the ability to "hide" audio or midi tracks that you are done with and don't need to see anymore. Craig Anderton taught me that trick on hiding midi tracks in a folder once you were done with them. Great way to clean up workspace when you're nearing the end of a project :)

You guys rock!
Made a folder for my synths, called it "All Keys" and its great! more space! 
With 28 tracks so far in the project, I can almost see them all at once!
Thanks again!
Peace!