Summary: To stay on top of your personal development, try learning new things like a programming language, an instrument, or exposure to a new field (e.g. biology or accounting). Exposure to new ideas helps you avoid confirmation bias and increase you willingness to explore your analysis further.
Summary: The foreach package provides parallel operations for many packages (including randomForest). Packages like gbm and caret have parallelization built into their functions. Other tools like bigmemory and ff solve handling large datasets with memory management.
My friend, Josh Jacquet, and I competed in the DMA’s 2016 Analytics Challenge (powered by EY) and placed 4th out of the 50 entrants. Given that the majority of the other contestants were agencies vying for a little exposure, I think we did well.
Summary: Clean Code is a clear guide to writing better software which can be applied to data mining and SQL queries. The Pragmatic Programmer is a more detailed but slightly more antiquated book. Code Complete is a massive tome full of specific guidance.
Summary: The US Census provides an API that lets you query any of their datasets. Includes population by race, gender, age, and more by zip code, state, congressional district, and a few other geographies.