Actually, the scan resolution is how high of a quality of image you want. The more dots per inch, the better the image looks. I generally scan manga and doujinshi at 300 dpi, just to be safe (some of those kanji can get pretty damn unreadable at anything less).
What you want to do to prevent cropping of areas you don't want is to go where it says Size. Right now, you have the radio button selected that says "Auto-crop the scanned item." If you want more control over what gets cropped and what doesn't, pick "Select area to be scanned," and in the drop-down menu, select what seems best. If there's a custom option provided, pick that.
no subject
What you want to do to prevent cropping of areas you don't want is to go where it says Size. Right now, you have the radio button selected that says "Auto-crop the scanned item." If you want more control over what gets cropped and what doesn't, pick "Select area to be scanned," and in the drop-down menu, select what seems best. If there's a custom option provided, pick that.
Hope this helps. ^_^