RegExing

I'm new to Reg Exing and I'm in a bind trying to learn it quickly enough to finish a component I'm working on. Basically I have converted a Word Doc to a text string, now I want to remove all "noise" words which I'm storing in an array. In addition, I want to remove all duplicates in the array so I only have one occurance of the "keywords." I will then store these in SQL Server to be searched on. Can someone point me to some help on how to use RegEx to perform the aformentioned tasks? I checked out the manual but I didn't find anything on how to do what i was looking to do. Thanks in advance, Ron