Not Another PDF Scanner
Not Another PDF Scanner 2, availabe here, is an open source program that should help you connect to a wide array of document scanners. NAPS 2 comes in particularly usefully when you are working with a device that will not do duplex scanning - fails to image both sides of a two-sided hard copy.
With NAPS 2 you scan in the odd numbered pages first, then flip the document and scan the even numbered pages. After both sides of the documents have been scanned, select 'Reorder . . . Interleave', and the pages will be re-arranged in the correct numerical order.
If you have a ADF that will only scan one side of a page, then when setting up the profile to scan a document, set the paper source to ‘Feeder’, not ‘Duplex’.
Under Advanced options, DO NOT select the checkbox to 'Flip duplexed pages'.