Please explain shares on a NAS

I have a simple DLink DNS-323 NAS, I want to set up an account on it for my wife and another account for myself. Actually each of us has a desktop and a laptop so does that mean I have to set up 4 separate accounts, maybe 2 groups with 2 accounts each?

Second question- for the names on the accounts do I match the user names for the 4 computers, the names that show up on the Windows login screens?

Third question- once this is done should those shares then become visible in Windows Explorer under network neighborhood and I just map them to drive letters?