Where can I find Dutch eBooks?
The Gutenberg site has tons of public domain books in Dutch:
You can find even more books in the Bibilotheek van de Nederlandse Letteren. https://www.dbnl.org This is a government site that digitizes Dutch literature written since the middle ages. Most PD books can be downloaded as PDFs.
Tons of free books but you need to read and understand Dutch at a high level before you're able to enjoy these, in particular books with old spellings or archaic language.