BugKick is an open source bug tracking and task management application (source is hosted on GitHub) that is “light” in means of features (which i sometimes nice).
Dotted Paper is just a free PDF file which makes wireframing/designing easier with the horizontal and vertical grid it has.
Nitro is a simple, good looking, free and open source task management application to get things done.
Those days nearly all project management applications can calculate the time that is being worked on projects to use them in various reports.
Collection of rules and red flags which help anyone navigate through every small project