Hi
@shadowfax, I have just started giving this a go. But it does look like you would have to be there a lot to gain any traction.
But to upload, click you Account avatar/photo, top right. That then brings up a menu band across the middle of your screen, to the right of your pic. There you will see a clickable link called 'Music'. Go onto that and you can upload from there.
It is not the most intuitive site I have come across, for sure, but I guess you just need to give it a bit of time. So I will have a go!