As all of us have already known, joomla (in term of website backup)was built and performed on 2 basic components that are mutually related namely; (1) Database, and (2) Joomla CMS (Joomla Files and Folders). In the event of web files getting corrupted, virus attack, problem during installation of Joomla extension, being hacked or other kind of malicious attacks, manual backup and restoration of these two component could probably your remaining last hope. This Joomla support publication will show you how to do it manually yourself.
As for general guide, a basic in website management for joomla based website is the installation of joomla on your live server. This tutorial will guide you on the principal knowledge on the installation of joomla which can be applied to previous and later version of JOOMLA 1.5.xx.
The common hack happened to JOOMLA based website is javascript iframe injection or Iframe hack. Although not serious in term of damage inflicted to the website, precautionary steps should be taken seriously. The nature of the attack is not just on platform based/dinamic(ie. Joomla, Wordpress, Drupal, etc.) website, it also attack a static website.