I used Noteworthy composer a few years ago, while it was easy to use, it was VERY crippled. However, it worked for me at the time. As my musical knowledge expanded, though, I started checking out other notation programs and for a short period of time composed with paper and pencil again.
In my opinion, Sibelius looked great but it took me a long time to get used to. I didn't think it was exactly what I wanted. Plus, it wasn't free. That's when I found Finale Notepad.
Finale NotePad is great. I used it for two years before buying the full-fledged Finale, though. I would recommend Finale NotePad for the beginner, but after using it for a while, you will want Finale Print Music or Finale.
When I used NotePad, I was working closely with the musicians playing my music, so I was able to make changes to the music as they played it and sometimes just ended up using it for sketches.
I still use NotePad on my laptop and my other computers, but on my main computer I use the full Finale. NotePad really helps me if I get an idea or need to make changes to a score and print out new copies during a rehearsal.