Honest question, comments above or under code?

In general, above the class, function, or method, but if details are needed for individual bits then at the end of the line or below (doesn't happen often).

However, a lot of commentary goes into tests rather than the code, and there I prefer to use doctests, a literate style that interleaves prose and code. In general, it follows this pattern: tell them what you're going to do (ie. prose), do it (code), explain what just happened (prose), and prove it did what you say (test code). Doctests are mostly integration/functional tests rather than unit tests.

Examples usually have it above.