Sample data sets available to the Data mining community

http://www.educationaldatamining.org/resources.html

https://pslcdatashop.web.cmu.edu/

International Working Group on Educational Data Mining

The aim is to support collaboration and scientific development in this new discipline, through the organization of workshops and mailing lists, as well as the development of community resources to support the sharing of data and techniques.
http://www.educationaldatamining.org/

Best site to Get an Understanding On DataWareHousing

http://www.learndatamodeling.com

Best blog for info on INFORMATICA

http://informatica-tutorials.blogspot.com/