Reading List setup to manage reader content and Read
Answering @Firedancer885 made me realize it may be helpful to new users of calibre and the Reading List plug-in if I gave more details on how I have my Reading Lists setup. I have inserted screen shots of my customer column and Reading List setups at the bottom of this posting. I hope this helps.
I have a fairly large collection of ebooks, so I needed a way of managing which books are on my Reader (Kindle) at any given time. I try to keep the number to around 50 at a time (just my own preference, this does not effect the setup/functionality). I also wanted to track which books I have already read.
I have set up a custom column to track the Reading List to which my book is currently assigned called book_status, since for me the purpose of my Reading Lists are to track the reading status of my eBooks. The name can be changed to something more appropriate to your needs, you will just need to refer to your fields name when setting up your lists. My Reading Lists are setup so my books can only be in one list at a time. If this is not preferable for your situation, you can define the custom column as a 'Tag like' text column instead.
I have three Reading Lists setup:
Shelf: These are the eBooks I currently have on my Reader. Adding a book to this list will queue it to be added to my Reader the next time I do a Reading List sync.
Read: These are the eBooks I have read. Adding a book to this list will queue it to be removed from my Reader the next time I do a Reading List sync.
Remove: These are eBooks I have not read, but wish to remove from my Reader. Adding a book to this list will queue it to be removed from my Reader the next time I do a Reading List sync. This list will be cleared after the sync.
Another great plug-in to have, which works great with the Reading List plug-in, is the Kindle Collections plug-in by @meme. @kiwidude as added hooks in Reading List to call Kindle Collections when a Reading List sync is performed, which is device/reader specific. Once you install Kindle Collections, go to the Reading List Devices tab and you will be able to set the Kindle Collections column to either Y (call Kindle Collections during sync) or N (don't).