It depends on what you mean by networked. I'm going to assume here that other computers/users will be accessing this folder/share.
Assuming its NTFS you will need to do three things for permissions:
1. Create a user account and password for each user that will access the files
1a. If there are seperate sets of permissions for different users they can be put in different groups
2. Right click each folder and select share
2a. Add the correct users and groups and set the share permissions
3. Right click the folders and select properties and then the security tab. Set the permissions for each user/group.