###Radare2 Book Maijin on GitHub is in the process of putting together an online book for Radare2. I’ve been looking for a good resource for using Radare2, and this is a great start.
###Reverse Engineering for Beginners Dennis Yurichev has a free eBook on Reverse Engineering. I haven’t gotten through it yet, but it looks interesting, and you can’t beat the price.
###Hacker Playbook Finally, I finished up The Hacker Playbook: Practical Guide To Penetration Testing this week. You can find my full review here.