I've got a server setup where a couple users will need access to the webroot and subfolders. How do I ensure that the files they upload have the proper permissions to be seen by apache and allow them to edit/delete files as necessary
Just add both users to a specific group and have that ftp path owned by that specific group.
You can achieve more advanced control (and inheritence!) over standard unix permissions and umasks with ACL's. As always, with more control comes more complexity.
Firstly the filesystem on your device needs to be mounted with the ACL option (assuming Linux extended file system here). This could already be available... if not:
You can add a default mount option to the device:
Now your're ready to get and set ACLs with
What you need is a default user/group permission on the directories which will then be inherited by any files contained or created within.
If you've not used ACLs before you might need to check some external tools that deal with files also support ACLs. Backups/Restores etc.