Switchboard to open two databases

[mslennb]

I have two distinct databases (Personnel and Revenue tracking) and I am trying to secure them and also create a switchboard for users (20+) to open and use. Some users need access to one or both databases. Some users need data entry/update rights to the tables/forms, and managers need read-only to view and print reports from one or both databases. I am thinking to create "group" accounts like "data entry" or "manager" groups rather than individual user IDs. I am using Access 2002, both databases are split into front end/back end and not secured on a network. Any assistance in how to set up security and the switchboard would be appreciated.
Thanks.