Now copy the file "WebOffice_SampleProject.mxd" from WebOffice10R3-DVD\SampleProject\projects\mxd to the directory ServiceDocuments in your <ArcGIS Server location> which has been created in chapter Generic WebOffice Servcies.
Note: You should store all map documents served by ArcGIS Server in this central location <ArcGIS Server location>\ServiceDocuments. This way you always know at one click about the map documents served by ArcGIS Server.
Note: If you have chosen a different location to store the Sample Project geodata then please check the file system access rights of the copied data files. ArcSOC user account respectively local Windows Users group must have read and write access rights.
For productive systems it is recommended not to use the Service Documents location but a local mxd editing location and to update mxds using the Refresh Project button of WebOffice author. See WebOffice10R3_UserManual.pdf, chapter File Menu for details.