Not quite sure what you are asking here.
It is standard practice to configure a server-based home directory for your users, which can be configured to map as a specific driver letter. (I know you’re planning on installing AD from other questions, so i assume you’re looking to get this into each person’s user object configuration?)
You can use Group Policy to redirect each user’s “My Documents” folder to their home directory and therefore protect their data – i.e. it can be backed up centrally.
Finally, you’ll probably need to look at a solution for laptop users where the My Documents folder is replicated locally for when they are offline. For this, you’ll use Offline Files which can be setup using Group Policy too.
Microsoft has a wealth of information on their website.