We've just had a request from our history department to www.questia.com to get access to all of it's books/journals. It looks pretty good but we're not keen on is the fact that we'd need to set up an individual account for each pupil user as it's got VLE style functionality.
There's also a yearly subscription required to access it and historically most of the online subscription resources we've signed up for seem to rarely get used to any good effect.

Does anyone know of any other good online library resources that contain books and PDF's they'd recommend for library/study use in schools?