Add an employee login to a wordpress page?

I am working on a proposal for a website for a customer. They have expressed a desire to have a password protected page on their site where they can place documentation and such for their employees and provide each employee with a unique login. They would need a backend in the WP-Admin to be able to create and remove accounts as necessary. I am looking for a plugin which could provide this feature. Might anyone know of such a plugin? Thanks in advance.

-Jason