iSleep adds a sleep timer to iTunes with a fade out effect. Type in how many minutes you need to sleep in, choose an option (Quit, Sleep, Shut down and more) and click "Go to bed." That's it. iSleep supports DVD Player too, the chosen action happens automatically at the end of the movie (manual timer available too if desired). A built-in alarm clock also plays iTunes at a desired date & time with a fade-in effect.You can also put your Mac to sleep and wake it up automatically to play music!
The program itself is quite simple. It does it's job though for only 8$. I enjoyed the options that came with it and I found them helpful here and there.