Depending on your experience and the time you have you could integrate your website with a content management system (CMS) such as Drupal, Wordpress, or Joomla. These are all great tools and would do everything you want and more. There is a slight learning curve to using these though.
Another option is to build your own CMS, but doing this would probably take more time then it would to learn one of the above mentioned CMS.
All 3 of the CMS's have large communities and you should be able to find tutorials by just googling for them.