Did you know that you can download your nookbooks (and books from a few other sites as well) directly into Calibre? This function has been included for awhile, but I've not really played with it much until recently. There's a lot to learn about using calibre, I'm slowly getting around to them all.
You can purchase your books within Calibre and download them into the calibre library. Once in your library, you can add them to your catalog if you create one, and/or use Calibre as your backup as well as having them in your library for easy reference!
First, I suggest you get the newest Calibre update and install it.
Go to "Get Books" in the menu bar. Click on the bar on the right side of the icon, from the pull down menu, choose "stores", then choose "Barnes and Noble".
A window will now pop up for the Barnes and Noble website. Within this window, you will have to sign in to BN each and every time you use it. Your password is not stored. I suggest you sign in before you do anything else.
Once signed in, you can browse and purchase your nookbooks or go straight to your Nook library.
Once in your library, you can now download any or all of your purchased books. Just click "download" for each book you want and your download will start. There's no magic pop up window to tell you it is happening, the books won't show up in your downloads folder. They go straight into your Calibre's library and are filed in the same manner as your other books.
At the bottom left of Calibre, it will tell you when each title is finished downloading. This is usually the long number/letter name that is given to your books that you usually find in your nook app folder, but Calibre will pull the title and author out for you and display it in the main library. VERY NICE.
Out of 80 books I downloaded today, one did not have an author listed once in Calibre, and another was displayed with it's generic name and unknown for author. Because I was downloading the books from the website, I was able to check back for what books weren't showing up, and made a notation on what books would need to be manually updated. Because the downloads are happening in the background, it's easy to think they aren't happening, but they are and they show up in the library as they are fnished downloading.
This was a lot easier than importing them from Nook for PC. There was no guessing what those untitled ebooks might be. And I didn't have to wait forever for Nook for PC to open and download and then become workable with my very good size library.
Though Amazon is listed as a store, it does not work this way, but does open Amazon in your browser rather than within Calibre. Kobo works the same as BN as I've used it for Kobo as well, to directly download my books into Calibre. Those are the only stores I've tried. There are a few other stores listed though, you can give them a shot.
I found this to be less stressful and more organized than just importing them and hoping for the best. I had more control over it, could pick and choose what I wanted downloaded as I did it.
I like keeping my BN books within Calibre both as a backup and to keep track of what I've purchased from different places so I don't accidentally repurchase something. I also can keep up with series where different books in the series might have been purchased at different stores. They are all stored under the same author in Calibre and I keep the series information there for reference. I keep a copy of my Calibre folder on my PC and on a usb drive just in case I lose the PC. Also, I can take it from one computer to another and have access to my books. LOVE it!
Hope you find this another useful way to get the most from your Calibre library!