There is are major problem with ebooks, or any digital archive, and that is what is the shelf life of the documents and if current technology fails then how do we read them. At least with paper books you don’t need electricity or computers to access the information.
io9 has a summary of a recent New Scientist article on just this topic:
A recent article by Tom Simonite and Michael Le Page in New Scientist tackles this question by positing a minor cataclysm: something bad enough to tear apart civilization as we know it, but not quite enough to kill off humans entirely. Candidates include a pandemic, a financial collapse that would make 2008’s pale in comparison, a severe natural disaster, or just the slow accumulation of decay in society’s foundations.
The question, then, is in the absence of most of the raw materials that powered the construction of our current industrial civilization – there wouldn’t be nearly enough fossil fuels to rebuild from scratch, for instance – whether the survivors of this collapse could make use of the one great resource we would leave behind in huge quantities: information. If we could leave behind the equivalent of a cheat sheet for these post-apocalyptic survivors, could they perhaps bypass the trial and error of rebuilding science and jump straight to the achievements of the 21st century?