Scikit Learn has a guide for machine learning techniques. Matthias Vallentin did a remarkable cheat sheet/cookbook for probability and statistics.
Many heavy summaries of econometric methods are presented in textbooks and articles.
But is there a brief summary of econometrics? Like when one should use GMM, or 2SLS versus OLS, or what to analyze time series with, and so on. Like a map that can be given to an applied economist. Or at least a summary table of econometric methods?