As for Scrum I would recommend reading "Scrum and XP from the trenchesScrum and XP from the trenches".
As for Kanban, you should listen to one of the great speaks from Pawel Brodzinski. He sells Kanban as easy as he is breathing. One link I found in no time: http://blog.brodzinski.com/2010/11/kanban-basics.html
As for Agile, it's a very large domain. Should we stick to Agile Manifesto only?