Proper way to give rights at the file system?

[jep at obrien-pifer.com (James Pifer)]

> There really isn't.  If you're going to give the person write access to 
> /usr you'd better really trust that person.  If you trust that person 
> enough to do that, you might as well just allow them to have root access 
> through sudo so you can keep track of their activities.

Let me give a few more details. The person will have to access this
through a portal, which will only allow access to the directories that I
specify. The backend portal process will connect to the system using
vsftp. So the user will not have wide open access to the system and they
will not even know the login info. 

So it sounds like I need to do chmod on all the files under that
directory? 

Do files inherently inherit the rights of the directory that contains
them? My concern is with new files that get created, even by root. If
they are in the directory that I give access to, it's assumed the user
can do what they want with it, as update or delete. 

Thanks,
James