Before we dive into creating projects and cases, it is important to understand how bug/issue tracking systems are constructed. Each issue has a finite start point and end point. In between the start and end points, there may be communication between the report of the bug and the person assigned to work on the bug. This communication is usually to gather more information or make notes about potential solutions to the problem being addressed. There are many different types of bug tracking programs available; some are Open Source, such as Open Atrium, while others may charge a flat fee or monthly fee to use a particular system. Some of the more popular bug tracking programs include the following:
Bugzilla: http://www.bugzilla.org
Unfuddle: http://unfuddle.com/
FogBugz: http://fogcreek.com/FogBugz/
Trac: http://trac.edgewall.org/
There are many other bug tracking programs available that you can find simply by searching...