This book dealt with Agile, Flexible, and Scrum terminology in several places. Every plugin has its own pros and cons. The Agile Dwarf plugin is definitely worth mentioning, because it drastically improves the manager's user experience by providing several dashboards to help visualize and speed up task management.
Server and Redmine administrator access is required.
Install the plugin just like any other regular plugin:
git clone https://github.com/acosonic/agile_dwarf.git plugins/agile_dwarf
rake redmine:plugins:migrate RAILS_ENV=production