You have certainly picked something relatively complicated if you don't have any programming experience. Coding such a script yourself would require learning PHP (or whatever other language you decide to use) quite well as several pages would be required in order to set up login, logout, register, lost password etc page before you even get to the point of adding code to all the member's area pages to ensure they are only accessible to members.
The more practical alternative for you without having to learn programming first would be to implement a script written by someone else that provides the member's area functionality.
If you are already using a script to generate your site then there might be a plugin that can add the member's area for you. For example
http://www.mytechopinion.com/2009/07...wordpress.html looks at several plugins that provide that functionality for WordPress based sites. If you are using Joomla then
http://www.joomlablog.co.za/joomla-t...a-in-joomla-15 provides step by step instructions for adding a member's area. For Drupal there are instructions at
http://www.ehow.com/how_8616135_tuto...ip-drupal.html - if you are using some other script then there might be a plugin available for it - you'll need to search to see what's available.
If you are not already using a script such as one of those mentioned then you can either implement one of them in order to add the member's area to your site via that script and its plugins or you can get a stand-alone script that allows you to add the functionality without needing one of those scripts. I wrote a script that provides all the necessary components to set up a member's area and offer it for sale at
http://www.felgall.com/php19.htm