These are some books written by members of the meetup.

Machine Learning for Hackers

Drew Conway & John Myles White

Parallel R

Q. Ethan McCallum

Doing Data Science

Cathy O'Neil and Rachel Schutt

Text Mining with R

Julia Silge & David Robinson

Analyzing the Analyzers

Harlan Harris, Sean Patrick Murphy & Marck Vaisman

Testing R Code

Richard Cotton

Bayesian Data Analysis

Andrew Gelman, John B. Carlin, Hal S. Stern, David B. Dunson, Aki Vehtari & Donald B. Rubin

Bad Data

Q. Ethan McCallum

Teaching Statistics: A Bag of Tricks

Andrew Gelman & Deborah Nolan

R for Everyone

Jared P. Lander

Applied Predictive Modeling

Max Kuhn & Kjell Johnson

A Quantitative Tour of the Social Sciences

Andrew Gelman & Jeronimo Cortina

Machine Learning for Email

Drew Conway & John Myles White