While FreeBookSpot is a useful supplement, several other platforms provide more reputable or expansive free ebook collections:
These platforms rely on public domain works (copyrights expired), so they are completely legal, safe, and supported by a global community of volunteers.
8/10 (docked for access complexity, but excellent for updated fiction).
If you prefer listening to reading, LibriVox offers thousands of free, public-domain audiobooks read by volunteers.