C#.net 2008 generics

Question

I am new to using generic classes and have not heard of them until I got this application to maintain. Thus, I am wondering what would you URLs should I look at to learn more about generics that point to database tables using XML.
I have a C#.net 2008 winodws application that I just obtained to maintenance. There is no documentation for this application and the programmers that wrote this application not longer work for this company.
 This application has one solutiuon file and has lots of project files. One of the project files is called 'datamapping' and uses the generic namespace. This project brings in lots of files with the 'using' statement.