First you need to create the table or text field with the values sent to the web test. I made a text file with one value in each row. Make sure there are no extra line feeds at the end of the file. Then add the data source to the web test.
Here's the MSDN article that describes adding the data source:
There's 2 important things to remember with data binding:
1) Select the data source under the QueryString Parameter or the Form Post Parameter - Properties>Value
2) the setting to iterate through all rows in a table or input file is entered in localtestrun.testrunconfig under Web Test there is a radio button called "Number of run iterations" - select One run per data source row
Here is the MSDN page with a walkthrough on adding data binding to a web test: http://msdn2.microsoft.com/en-us/library/ms243142(VS.80).aspx