At least in Office 2000, you can assign a "Workgroup Templates" folder in
Tools: Options: File Locations. Our computers all have this set to a shared directory on the server so that new and modified templates are available instantly.
If you are distributing them for remote and laptop users, the user template directory
usually can be accessed as "%USERPROFILE%\Application Data\Microsoft\Templates" (on NT/2k/XP/Vista, where %USERPROFILE% expands to the current user's documents and settings folder). Again, that's where my version of Office seems to put it by default. Look in
File Locations to see if it's the same on your installations.
To add specific templates to the shell's
new menu is a bit tricky, and it's unclear whether you can add multiple templates for the same program type, but this
PC World article is a good place to start.
However, messing with the registry is not my first choice: you might be better off adding a
Common Templates folder to the Start menu and having shortcuts to the template files in there instead.