We're working on tutorials, they're just not ready yet for that feature.
But the basic idea is this: NoteTracker takes notes for you on opponents in situations you specify. If you look at the defaults in the cash game side it should give you a basic idea of some of the things that you can do. For example, you can have NoteTracker take a note when a player 3Bets and you know his hand - and then it will show you that he 3bet with that particular hand in the past. Using NoteTracker to help you figure out an opponent's range is a very powerful tool, but you can also use it to keep track of times an opponent did something that is just very strange as well (for example, folding when getting 2 to 1 or more on the rest of the money in his stack or some such).
Everything is done using our filter mechanism, so when a player matches a filter set as defined the note is taken. You can feel free to create test notes and test them on the Test page - play around with it, I promise you can't break anything