Apple's Scanner Compatibility List
DEVONthink Pro Office uses Image Capture, Mac OS X’s own scanning framework, for accessing flat bed scanners, all-in-one devices, and document scanners (the Fujitsu ScanSnap is an exception, it uses a proprietary driver software). How would you know that your scanner is compatible? Simply try it. But, finally, with Mac OS X 10.6 ‘Snow Leopard’, there is a simpler way: Apple has published a list of compatible scanners: Click here to look up your scanner. Thank you, Apple!
BTW: If your scanner is not supported by Image Capture, don't despair. DEVONthink Pro Office also comes with the TWAIN scan software ExactScan Capture built-in. And if this also does not work you can use the scan software provided by your scanner and have it send completed scans to DEVONthink Pro Office which will happily pick them up. See DEVONthink Pro Office's integrated help, chapter 'Email, Scanning, Web-Sharing' for more about using your scanner with DEVONthink.