I’m continuing my class-prep practice of searching through Cross-Validated questions with tags corresponding to upcoming class topics, and here are some interesting ones I found about data transformations:
http://stats.stackexchange.com/questions/46418/why-is-the-square-root-transformation-recommended-for-count-data
http://stats.stackexchange.com/questions/1444/how-should-i-transform-non-negative-data-including-zeros
http://stats.stackexchange.com/questions/27951/when-are-log-scales-appropriate
http://stats.stackexchange.com/questions/90149/pitfalls-to-avoid-when-transforming-data
http://stats.stackexchange.com/questions/60777/what-are-the-assumptions-of-negative-binomial-regression
The last one isn’t really about data transformations, but is still interesting.
Healthy Algorithms 