Some resources and useful information about this development technique:

• About Scrum (Spanish) http://www.proyectosagiles.org/
• Agile Software Development http://www.agile-software-development.com/
• Good Agile Project Management software, community / free version available http://www.rallydev.com/
• Scrum project management software, for Windows (Desktop) http://www.scrumdesk.com
• MoSCoW method to prioritize tasks http://en.wikipedia.org/wiki/MoSCoW_Method

Basic concepts:

• Sprints (iterations) last from 2 to 4 weeks, and they are released so that the client can test and provide feedback
  • Every iteration is divided into small tasks planned to be achieved in less than 2 days work
• The specifications for a started sprint should not change, the client has the responsibility to define carefully the priorities; they are defined as user stories
• There is a project owner which interacts with the client, and a facilitator which helps the development team to achieve the goals
• From 5 to 9 people in every development team
• Daily meetings (about 15 min) with all the team to discuss about:
  • The work done the day before
  • The problems faced when doing it
  • The work to be done the same day
  • Only ‘pigs’ can talk, ‘chickens’ can listen, though
• ‘Pigs’ are: developers, project owner and project facilitator; chickens are: clients, users, marketing people
• Finish every new feature (sprint) at 100%; it is better off having 80% features at 100% than 100% features at 80%