To the list including these MobileRead Forums and the other sites others listed above, I add the following legitimate sites:
And these Barnes & Noble blog and bookclubs forums:
The list above overlaps slightly with Provo Library's list of
Free eBook and Lending Sites.
And, of course, you can also borrow ebooks and audiobooks from the public library. Click this link to access MobileRead's list of
Ebook Lending Libraries.