the first thing to decide is what the database development platform will be.... as cyberM noted, Access probably will not work in this case, it could, but it also depends on how you want to update this central db.... as well as the number of concurrent users, and the amount of data you want to deal with. SQL Server, Oracle, and probably even mySQL would probably be better - they're going to scale better than Access.

Once you decide that, then further decisions can be made on how to design the rest of the system.

-tg