[Rbneader]

You want everything in Calibre. I'm managing ~10,000 books and it works well if a bit slowly. It takes a bit of work to set up but makes life a lot easier integrating multiple sources of books.

Tips:

* Make sure to add the Apprentice Alf plugins so you don't run into any issues with store-only books. Otherwise your books might have trouble being imported into Calibre or sent to your device.

* You can set up auto-merge settings so that if Calibre detects you are adding a duplicate book it just merges the records. This is not foolproof - sometimes it doesn't detect identical books or it thinks a book is the same even though it's a different edition or version. But it helps a lot.

* You can add metadata in Calibre that will help organize your books on your Mac. Also, some ereaders or ereading apps recognize Calibre tags. I prefer the FBReader app.

* You can use Calibre to update book titles to indicate if they are in a series or other key facts, if your ereader doesn't recognize Calibre tags.

* When editing metadata in Calibre, you can use tag search/replace to standardize tags. EX: I got several books tagged Action, Adventure, Action/Adventure, Action & Adventure, etc. I used tag search/replace to make them all the same tag without having to update each one individually.

* If you have a favorite TV show or movie, you can find free fanfiction for it and download that into ebooks with Calibre and the FanFicFare plugin. It's a nice little extra.