Are you talking about the option in Dreamweaver or are you looking for another space just to test this on?
I've been a DW user for a long time and I think because I don't do a ton of DB work that whole section won't ever mean much to myself.
The point being it's for use with Databases and not HTML or the like.
No on this log in are you only going to have 1 generic account or as many as needed for incoming visitors to sign up for.
Plus what will behind this closed door? You might want to dump this idea and just go with a CMS like PHP-Nuke or Post-Nuke where you can have this all done up for you and visable to only registred & logged in users.