Hi Ritarun, think of resolution at a fixed size as on a sliding scale. If it operates like mine, I think you'll see that as you increase the dimensional size, your resolution option will be reduced. That is, at 100% original size, you'll have the option of a maximum scan resolution of 3000 ppi. However, at 300% original size, you'll only be able to scan at a maximum of 1000 ppi (assuming NO interpolation is taking place). If you don't know what sizes of prints you will be wanting to produce from your scan, scanning at the max resolution at 100% is fine. Once you bring it into your photo editing software, you can change the dimensional size (and you'll see the resolution decrease - sliding scale). You can enlarge the image to a size that compliments the recommended input resolution of your printer. For example, in my case, 300ppi-360ppi for output at 1400 to 2800dpi (which would equate to a 12x18inch print having used a 4000ppi scanner, no interpolation or resampling).
Hope this helps.
