Try the play music app already installed on the nex7.
When usb tethered to my win box, I right click an album folder, send to nexus 7, which puts it in the /music folder where play music (headphones icon) will find it.
You may need to convert the cds to mp3 format, called ripping, first.
Windows media player can do this for you as well as adding album cover art.
If you are using apple, someone else will help you.
If you are syncing from the itunes app, you may need to update itunes for the newer nexus 7 file structure.