I had a question about splitting. Would this allow multiple users to use the database at once?
Yes, for Access 2003, you can have up to 255 concurrent users (not sure which version you are using--you can check Microsoft's website for specs on other versions)
If two people are working on data entry how does the db know how to store the data without overwriting
If entering new records, Access uses the primary key field to distinguish records.
If editing existing records, Access will lock the record being edited so only one user can edit at a time.
I know it is a continous connection from FE to BE but how does it work with two users?
As long as there is a bound form open in any of the front ends, Access maintains the connection to the backend.
Could I still split and use the FE on the network drive?
No, doing this can corrupt the front end and possibly the backend.
Can't I just convert the .mdb to and .mde for the user to run?
I'm not sure I understand your question. I haven't worked with Access runtime, but I thought it was geared more for those who did not have Access loaded on their computers. Even in the runtime you would still have front and backends.
I don't want to deploy FE's to each computer because there are only a select few people that will use the database
Just deploy the frontend to those who will be using the database. You can even split the database for yourself to try it out. Split the database, put the backend on the server and the frontend on your harddrive and see how it works. Then when you need to have others use it, just give them a copy of the frontend.