I have seen it all now.
There are some sites that apparently share books in pdf format, including textbooks.
I haven't tried any yet, so not sure how they works. However, it seems the file size is smaller than with music, so it should be quicker.
Of course, legal disclaimer, if you like something you "preview", delete the file & then purchase it from amazon or get it from the library, w/e (c) Ghostface & Fux