Syncing OneNote 2010 to SkyDrive
I am still waiting for my WP7 device to arrive, but maybe I can help with OneNote itself. I use OneNote 2010 on one of my work PCs. I save/sync it to my SkyDrive account.
For initial setup I think I went under the Home Tab of OneNote and near the bottom is the option to "Save to Web". It should prompt you for your Windows Live ID. Then save within your SkyDrive account. After initial setup it syncs by itself if you are logged into Windows Live. (If not the icon lets you know and prompts for your ID and password.)
If it doesn't directly lead you through, note the specific document address of the OneNote book that you want sync up. Then from your Hotmail account, roll over the "Windows Live" text in the upper left-hand corner. Within the drop-down box should be "Skydrive". From there find "add files" and select your OneNote book.
I'm too cheap to spring for OneNote 2010 for my home PC so I just re-open it from my SkyDrive and select "Edit In Browser". Otherwise it shows the option to "Open in OneNote 2010". Either way it is great to have all my work notes with me at home. (And on my phone, hopefully soon.)
I would imagine that syncing up OneNote Mobile should be just as painless. I used it on my old Touch Pro, and as archaic as it was compared to the WP7 version, I used it all of the time. I just didn't know how to sync it up back then.
I make it sound confusing, but once you get into it, it shouldn't be too bad.
Let me know if I missed a step and left you hanging!