[nobody7290]

The besshared folder is a folder which can be located on any machine in your network, most likely it is on your bes server.
Inside the folder you can put wallpapers and certificates which will be installed on the handheld during activation.

You find it, when you open the bes10 server console, open blackberry solution topology, blackberry domain, component view, then click blackberry administration service.
On the right side scroll down to "network drive".