Do you want to actually administer you music stored on My Cloud using iTunes program or just listen to it from My Cloud? If you want to administer it it this way I suggest you read through the iTunes help regarding storing the iTunes Media folder somewhere other than the default folder.
As for what I do, I just copy my iTunes Media folder to My Cloud (I store it in the Default folder Public/Shared Music folder) and I can access it all kinds of ways, from any devices or programs that can do so (including iPad, media player, etc). This includes using the My Cloud mobile app on iPad or phone. I can even access the iTunes Media folder remotely from anywhere.
Of course, doing it this way requires me to manually update the copied folder and occasionally, erasing the copied folder and re-copying it from my PC to the My Cloud again to assure it is up to date. A bit of a hassle, but I is not hard to do for me.