I recently joined the Society of Indiana Archivists, mostly because I think genealogists should be on really good terms with librarians and archivists. Plus it was cheap--only $5 for seniors [and unfortunately I am].
While looking at the SIA website, www.inarchivists.org, I found a good Powerpoint presentation, converted to an Adobe Acrobat file, on how to scan and to digitize materials. This was used in their Fall 2012 Workshop and is extensive--132 slides--and comprehensive. There's no narration, of course, but most of it is self-explanatory.
Check it out; I learned several things and so might you! And why not join SIA?