When scanning a bound document (i.e. a book), a dual-page scan, which scans both pages simultaneously, is easiest. You can increase recognition quality, though, by splitting the two sides after scanning, in order to perform recognition, layout analysis, and de-skewing (if necessary).
To split a dual page:
This command splits each dual page into two batch pages. See "General Information on Working with Batches" for more information on batches.
Note: If a dual page has been split incorrectly, deselect the Split dual pages checkbox and re-scan the dual page, or add the page images to the batch again. Finally, try to split the image manually using the Split Image dialog (Image>Split Image).