I don't understand how people are having all these vista problems. I have
installed Vista on no less than 5 machines and they all work very well.
There's a couple annoyances like disk activity and battery life but it all
works. Personally, I think if your technician's solution to a problem is to
uninstall Vista and install XP then you should probably find a better
technician.
Anyhow, here's the deal. "Shared Documents" and "Public" in Vista are the
same concept, they're just named differently. These folders are accessible
to all other users on the computer. It has nothing at all to do with network
sharing. To share a folder, you can go into the Network and Sharing Center.
There you can turn on file sharing and public folder sharing. This exposes
the user and public folders on the network so that they can be accessed from
another computer.
But now of course Vista doesn't just expose the folders to anyone on the
network. If that were the case, anybody in a Starbucks could access them
while you're on the same access point. So how does one computer get access
to another? Well you need to have user accounts on both machines with the
same username and password. So if your username is "John Doe" and you have a
password of "mypassword" on Computer 1, then you need to have a user account
with the same password on Computer 2. Then you can browse to shared folders
on the other computer and you'll have the same permissions as if you were on
the computer locally.
How this applies to OneNote is that on one computer you've got all your
notebooks stored locally, on the other computer you can open the shared
notebook by doing File -> Open Notebook then type something like
\\COMPUTER2\John Doe\Documents\OneNote Notebooks\Etc (you can browse for it
too, or your email link should work).
By the way, this behavior is exactly the same as Windows XP except that
Vista provides a much more user friendly user interface to enable sharing.
I'm not a networking expert by any means but I do this all the time. I have
a desktop, a Tablet PC, and a UMPC all sync'd up this way.