How do you make donations tax deductible?

I am part of an upcoming club/charity at my local highschool in Connecticut and our first event is in a little bit. We realize that legally large donations are supposed to be tax deductible (and in the town we are from it's a sure thing we'll see a few) but the question really is; from the receiving end of the donations do we need to do anything to allow our patrons to have their donation somewhat subsidized when their taxes come around?