I love digging into self-improvement books, and there are so many hidden gems online if you know where to look! Project Gutenberg is my go-to—it’s a treasure trove of classic self-help titles like 'As a Man Thinketh' and 'The Art of Public Speaking,' all free because they’re in the public domain. The interface feels a bit old-school, but the content is gold.
Another spot I frequent is Open Library. You can borrow modern self-help ebooks for free, almost like a digital library. The waitlists can be long for popular titles, but it’s worth it. Also, don’t overlook blogs like Medium or Substack—many authors share bite-sized self-help advice that’s just as impactful as full books.