The iClould backup does not include non-iTunes purchased music unless you subscribe to the paid iTunes Match service.
To sync to the iPod:
-You can't backup your non-itunes purchased music.
-There is a limit : 5 GB for free
the biggest you can get is 50 GB but for 80 € a year
- To transfer your music from your iTunes into your iDevice, you just need you USB cable and to plug it in your computer. Then just select the music you want to transfer from your itunes library and then slide it into to your iDevice Library, which appeares on your left.
Hope i answerd your question !