If you want chess books as PDFs or other formats without paying for them, then search for chess books at the Internet Archive or GoogleBooks. There are hundreds of chess books that are old enough that the copyright has expired. Moreover, most of them are full of games that are not in any databases. That's right, original material.
If you want free PDFs of chess books that are still under copyright, I'm gonna help shut down your forum thread.
chess.com needs a "like" button...
If you want chess books as PDFs or other formats without paying for them, then search for chess books at the Internet Archive or GoogleBooks. There are hundreds of chess books that are old enough that the copyright has expired. Moreover, most of them are full of games that are not in any databases. That's right, original material.
If you want free PDFs of chess books that are still under copyright, I'm gonna help shut down your forum thread.