Creating a Login Page for Dreamweaver mx

Hi,
Im pretty new to web design and coding, basically a newbie, and im trying to create a login page for a site using dreamweaver mx, and when i go to create a user name and password box it asks for the document type and to set up the sites testing server and was just trying to figure out how to go about this,
ive read a little into using phpdev, and wondering if using it will effect the system at work.
please if anyone can help
thanks heaps, Sam