Here is a little something to help you decide on your permissions.
No Access (None) (None) permission restricts all access to the shared folder. Specifying No Access for a user eliminates that user's access to the folder, even if the user is a member of a group or groups that have access to the folder.
List (RX) (Not Specified) permission allows the user to view a list of files and subfolders contained within the folder, and to change to a subfolder, but it doesn't grant permission to access the files.
Read (RX) (RX) permission grants all the rights provided by list permission. It allows the user to open a file in read-only mode, but not to write to the file or delete it. Because read (R) permission implies execute (X) permission, if the file is an executable program file, read permission allows you to execute it.
Add (WX) (Not Specified) permission allows the user to create new files and new subfolders within the folder, but doesn't grant permission to access the files, including those newly created.
Add & Read (RWX) (RX) permission combines the rights granted by the Read and Add folder permissions described in the preceding items.
Change (RWXD) (RWXD) permission grants all the rights provided by the Add & Read permission, and adds the rights to write (W) to and delete (D) files and to delete (D) subfolders.
Full Control (All) (All) permission grants all the rights provided by the Change permission, and adds the rights to change NTFS file access permissions and folder permissions, as well as take ownership of NTFS files and folders.
Special Directory Access permission allows you to customize folder access permissions. You can specify any combination of read (R), write (W), execute (X), delete (D), change permissions (P), and take ownership (O). For example, you can use special directory access folder access permissions to allow a specified user or group to have list and read permissions for files within the folder, but not to have the execute permission.
Hope this helps. ;-)