We just wanted to mention one of our favorite applications for Mac (though it’s also available for Windows). It’s called Calibre. It’s free and open-source. You can use it to manage and create eBooks as well as syncing ebooks to other devices.
We love to use it for converting our PDFs to eBook format. We also like the level of detail in how we can organize things. You can set up groups by Author, Series, Format, Publisher and many other little identifiers to get them set up the way you need for easy finding and sorting.
You can download the application from the link below: