The two HN discussions I found that seemed to have useful info on cohort analysis:
https://news.ycombinator.com/item?id=5245571 (Cohort analysis - User retention in a Rails application, 203 days ago)
https://news.ycombinator.com/item?id=4122000 (How we reduced our cancellation rate by 87.5%, 450 days ago)
The second link references the following class: http://www.skillshare.com/classes/business/Data-to-Dollars-U... ($35; 90 minutes in NY)