Usually, the concept is first you need to have a default login page.
Within that page, you will give an link option to your audience/visitor to register (register.htm) if they don't have a login username and password.
For example, in your register page, ask for information you need and they are
willing to give, say email, name, address, age, gender, username, password, etc.
Once they completed there registration, all information will be stored in your
database. If they forget there username/password, have another link for your audience their email & reset there username/password and confirm via email.
Hope this helps,