how to use the articals on this web site?

Question

Hi All
 I want to use the articals from this site in a vb.net 2010 project that I am writing. I don't understand how to REF. or IMPORT or whatever to use them. If I download an artical, run it it works fine but How do I add them to my code???????
 I have tried to REF. them, tried to add them,,, I don't understand what I need to do to use them, can someone help, please!.....at a total lose,Ron.