I come across so much 'interesting' stuff on the web re books (and every darn thing lol), that I installed Evernote some time ago now and my golly it gets some use.
It's free and I use it on my PC, lap top, phone and tablet (it auto syncs).
Here are some of the notebook names relating to books:
Books
Book buying sites
Calibre
Paper Back books read, therefore not in Calibre
Copyright
DRM
E Libraries
Specific authors ....
And then there are Notebooks on heaps of other non book stuff, even Beer!!
I also use Wunderlist to remind me to do stuff generally, book and non book related.
So, I'm curious what software do you use to keep your non Calibre and book related info in?