Yeah, is cool and not-in-the-hundreds-expensive.
I highly recommend using the keyboard, like in most programs.
Check the F2 for RSE, makes a difference. After putting it on,
check that the instrument (press F7) is really using RSE and not standard crappy midi sounds.
Well, its still crappy if using distorted sounds.
I put notes with clicking with mouse and jumping forward with arrows on keyboard.
A --> as shift+a opens the make-and-insert-chord, thats a funny one to play with.
F5 -> Score info
F6 -> the track your on
F7 -> instruments
etc.
I suggest loading up some song and hitting on that keyboard with a rage of a maniac
ie. just check out the most important, --> F1