A collection of useful links and websites:

R

Tidyverse - Best place to start your R journey
Ggplot2 - The best plotting package
Regular expressions in R - From UBC Stat 545. The website also contains great materials to learn R
Advanced R - When you want to dive deeper into R programming
Tidy Eval - Simple examples on creating your own programming code for functions that rely on non-standard evaluation
Cheatsheets!
Shiny guide - Most comprehensive and useful guide from the official source
Sparklyr - Dplyr on spark and another reason why the R ecosystem is so great
R-bloggers - For the dose of R-inspiration

Python

Python module of the week - Standard library simplified
Spark ML reference guide - Clear examples and use cases
Michael Yin’s Scrapy tutorial - Clear and comprehensive tutorial on scrapy
Jeff Knupp’s blog - Useful guide to OOP in Python

Data Science

Fast AI Courses - Really useful tips for practisioners
Kaggle blog - I love the winners’ interview section
McCormick’s word2vec tutorial - Best explanation of word embeddings
Kdnuggets - Top data science stories from the web
The Riddler - If you have some time to spare
Gelman’s blog - If you want to go to the dark side
Uber enginerring blog - Good read on how Uber tackles their engineering / data science problems
Facebook research blog - Another good applied blog
Journal of Economic Perspectives - Nice economic articles that are relatively non-technical
NBER digest - Concise write-ups from the economics field