Here's a reasonable one: "Agile Testing: A Practical Guide for Testers and Agile Teams." Lisa Crispin & Janet Gregory
There's nothing compared to hands-on experience (IMHO), but the book does provide a reasonable explanation of how testers fit into Agile. Don't take it as absolute truth (no Agile text is), but it's not a bad start.
You can get it through some source i guess,An average amount of books in terms of their content should be the preference.For getting some info about it see Innovative Agiles - agile with scrum methodology i am sure you will get some appropriate stuff from this source.