La Central Madrid
What is not to like about a book store with a coffee/lunch spot inside where you can immediately dive into your new bought books! This bookstore in the centre of Madrid is a beautiful old three floor building where you can easily spent a few hours sniffing between all the books, notebooks and other stuff they are selling.
After sniffing and shopping go downstairs to the bistro to have a coffee and something to eat. Or just come to this café with your laptop to work all day. The good thing is that they are open till midnight most of the days, so you can work until the late hours here when you have a deadline.
They also organize different events and presentations in the basement, El Garito. Check there website for the upcoming events.
La Central, Calle del Postigo de San Martin 8, Sol, Madrid