Access supports multi-user databases within a single .mdb file, so you don't need to split your database into front end and back end unless you encounter performance issues due to database size / number of users etc.
To configure an Access 2000 or later database in this way:
-- Make sure the .mdb file is held on a shared drive which all users can access.
-- Implement user and group security, to make sure there is only one Administrator with rights to open the database exclusively. This is not essential, but from my experience is definitely 'highly recommended'
-- Open the database as Administrator, and choose the Tools ... Options menu option.
-- Click the [Advanced] tab
-- Set these options:
Default open mode = Shared
Default record locking = Edited records
Tick the 'Open databases using record-level locking' check box.
I use this configuration on a 25 Mb database used by up to six concurrent users, with no problems.
I hope that this helps.
Bob Stubbs