Member login

I am looking for a host for my non-profit organization’s website. My most important requirement is to have the capabiliy for members to set up a user name and password for themselves that would give them access to the member directory. The administrator should be able to accept or deny any such application. This probably sounds pretty basic, but I am not in any way an expert at this. Does DreamHost offer something like this that would be easy for me to set-up?