calibre, and specifically the Editor, will allow you to
create ebooks. KDP will allow you to
publish them.
It's not a bad idea to put up ebooks on the Kindle Store, that have been edited to meet your requirements. I'd like to point out, though, that the only benefit over using calibre to convert and sideload the book (or kindlegen for the conversion) is the Whispersync -- cloud storage, annotations -- without suffering the flaws in the
Personal Documents service.
Also, MobileRead has a public domain ebook library lovingly compiled by our members, so check if they are already available, if not, perhaps you could share them here as well!
