Rapid Reporter, exploratory notetaking

http://testing.gershon.info/reporter/

Agile Record - The Magazine for Agile Developers and Agile Testers

http://www.agilerecord.com/

Agile Testing Days

http://www.agiletestingdays.com/

Verification Validation | XING

https://www.xing.com/net/verval/

Agile Record - The Magazine for Agile Developers and Agile Testers

http://www.agilerecord.com/index.html

InfoQ: Tracking change and innovation in the enterprise software development community

http://www.infoq.com/

Developing Skills as an Exploratory Tester (C.Kaner 2007)

http://www.kaner.com/pdfs/ExploratorySkillsQAI2007.pdf