I take this directly from Resource Shelf, with permission, because it’s an important post for anyone in the scholarly world.
The September issue of Reviews in History via the The Institute of Historical Research in London offers reviews of four scholarly e-book services.
All four of the e-Book services were reviewed by Mark Herring, Winthrop University. They’re in-depth looks at each product (we’re providing only a snippet) and we strongly suggest reading the complete review.
The reviews are of Gutenberg-e, Humanities E-Books, Oxford Scholarship Online, and Medieval Sources Online (which is the one that especially interests me). I haven’t had time to check them out yet, but I will be doing that soon.