A .csv (comma separated values) file is a very simple text file that allows data to be easily parsed as it follows a simple rule set. The best way to create a .csv file is right within a spreadsheet application such as Excel or Google Doc spreadsheet.
Go to File -> Save as -> and under 'Save as type' -> CSV (Comma delimited)
Google Doc Spreadsheet:
Go to File -> Download as -> CSV (current sheet)
If you have any questions, feel free to reach us at firstname.lastname@example.org