Thanks for your post! After about 25 minutes of trial and error I was able to get it working.

I started by creating a document manager under the business applications, as you advised. I then created a document library by clicking the little add button (it comes up as a new tab). I had to create a folder within the library to store the notebook in. That pretty much did it.

However, mine is saved under username.officelive.com/Notebook/Onenote/Forms/AllItems.aspx/NotebookName

You might have to play with the address. I'll throw a guide up with screen shots later. Good luck!