Hiya Tom
You'll need an OCR (Optical Character Recognition) programme to edit scanned text, you usually get it in the bundle with your scanner (Usually not very good) if you want to pay I think the best ones are Abbeyfinereader and Iris Pro, Google for them, could get them cheaper if you use auctions. Here is a free one that's not bad, try download 4.
Download SimpleOCR SDK DavidB.