Plenty of free e-books in Mobipocket format show up fine on Kindle.
Use Mobipocket software to convert PDFs to that format so you can read them on Kindle.
As glued to the net as we all are, there's vast quantities of content that is not available online.
The Kindle has many flaws, but it does allow you to read a few different non-DRM formats.
A revolutionary portable reader that wirelessly downloads books, newspapers, magazines and blogs to a crisp, high-resolution electronic paper display that looks and reads like real paper, even in bright sunlight.