I use Selenium scripts to do regression testing and I have all the test data in excel. This helps me manage the test data.
When doing regression testing you should have a standard data to test your application. If you are getting the data from the database to run the regression suite and if something fails you are not sure if its because of the test data from the database or because of the changes to the application.
So, I prefer to keep the test data in excel and use it in my selenium scripts.
I hope this will give you an idea of preparing the test data.
Here is code for you to read the data from excel:
string CPPath = @"c:\TestData\HFControlPanel.xls";
Microsoft.Office.Interop.Excel.Application CPapp = new excel.Application();
// create the workbook object by opening the excel file.
excel.Workbook CPworkBook = CPapp.Workbooks.Open(CPPath, 0, true, 5, "", "", true, excel.XlPlatform.xlWindows, "\t", false, false, 0, true, 1, 0);
// Get The Active Worksheet Using Sheet Name Or Active Sheet
ObjectReference ObjectRef = new ObjectReference();
excel.Worksheet CPworkSheet = (worksheet)CPworkBook.Worksheets.get_Item("ControlPanel");
string CPCountry = ((excel.Range)CPworkSheet.get_Range("SelectCountry", Type.Missing)).Value2 as string;