I believe it is of vital importance to read to keep upto date with the latest technologies and the advancements that are being made to existing technologies. To keep up-to date with what is going on I read a number of blog posts. To deep dive into a topic I tend to lean more towards books as this often gives a broader coverage of the area and also allows the author to go as deep as they need with the subject matter when they feel it is required.
Below is a list of the sources I find useful and hopefully people who come across the is resource will find them equally as useful.
The Goal - Eliyahu M. Goldratt
The Pheonix Project - Gene Kim & Kevin Behr
How to win friends and influence people in the digital age - Dale Carnegie
The One Thing - Gary Keller & Jay Papasan
The Chimp Paradox - Dr Steve Peters
Don't make me think - Steve Krug
Javascript: the good parts - Douglas Crockford
Pragmatic Programmer - Andrew Hunt & David Thomas
Growing Object Orientated Systems - Steve Freeman & Nat Pryce
Get Programming with F#: A guide for .NET developers - Isaac Abraham
Head First Design Patterns - Eric Freeman & Elisabeth Robson
Joel on software - Joel Spolsky