If this is to be a multiuser db then you will want to split it.  This entails
putting only the tables in a db (called the backend) and linking those tables
to db's for each user (called frontends).  You will want the frontends to be
MDEs.  MS does all the work for you  by selecting Tools, Database utilities,
Make MDE file with your frontend db open.  Store your original frontend mdb
file someplace secure (your computer) because if you decide to make changes
in the MDEs you have to make them in the MDB and then make a new MDE.
Once you make one MDE you can copy it to the various users computers.  You
amy have to relink the backend tables if the network drives aren't mapped the
same way on all the computers but this can be done via Tools, Database
Utilities, Linked table manager.
As far as the Intro screen, you can "roll your own" menu form, create a
Switchboard through Access, or create a Customized toolbar (to use the latter
two type switchboard or toolbar in the Access help and select the item that
has create for either.
You also have Startup options that tell access how to behave when you open
that db from Tools, Startup...
Hope this helps,
Bob