Yep - I have three different PC laptops in my house all linked up to my Mac Mini Server. Works just fine. Basically you just need to
- create a workgroup on the mac Mini Server
- create user accounts in the Mac Mini server, which mach the names of the user accounts on each PC
- put those user accounts in the workrgoup
- create shared folders with SMB file sharing turned on
- and grant that workgroup access to the shared folders with either read only, read & write or whatever type of permission you want
This will allow you to see Mac Mini, shared folders on it and their contents, from the Network Neighbourhood view on each PC.