From the list at Free Programming Books, here are those I wish to consume.
- Git Magic
- Think like (a) Git
- A Byte of VIM
- Git Reference
- Git from the Bottom Up
- Learn VimScript the Hard Way
- Learn VIM progressively
- Sed - An Introduction and Tutorial
- Rust for Rubyists
- Ruby User's Guide
- Ruby Hacking Guide
- The Bastards Book of Ruby
- The Bastards Book of Regular Expressions
- MacRuby - O'Reilly
- Programming in LUA
- Getting Started with Grails - 2nd Edition
- GO by Example
- Object Oriented Programming with Objective-C
- The Little Book on CoffeeScript - O'Reilly
- BASH Guide for Beginners
- Understanding map and reduce
- Learn Python the Hard Way, 3rd Edition
Not on the list of Free books, but I just completed Heroku: Up and Running.