Copy the directory tree from the tarball (or zip archive) to a location suitable for serving web pages.
With your web browser, go the location where you installed the package. You will be presented with a web page that will help you configure and install the application.
After completing the installation, login and start reporting bugs.
Optional: Install JpGraph (http://www.aditus.nu/jpgraph) if you wish to use it for the summary bug display on the home page.