As Sean said.. you will want to scan it at the higest resoulution possible for minimal loss in image quality. For my larger printed works I have had files in the range of 250 - 500 meg as uncomprssed .tiff's. Just to give you an idea.. the 500+ meg ones were for prints in the 20x24 size. These are drum scanned 4x5 negatives/positives. I know it might seem tedius to scan at that high.. but it is needed for good print output. Web ouput can be much smaller.