Well there are lots of methods to deal with this, however to save you a lot of troubles you may want to setup an import table to do your scrubbing then move to the main table. But the basics of finding duplicate goes soemthing like this

SELECT COLUMNS FROM tblX HAVING COUNT(DUPICATETOCHECKFOR) > 1 GROUP BY COLUMNS

Just dig around in the scripts here but to give you an idea of what best woirks for your needs a DDL of the table and sample of type of data would be helpfull.

"Don't roll your eyes at me. I will tape them in place." (Teacher on Boston Public)