Where do you start learning to implement code coverage tools?

I want to implement a code coverage tool to learn about different coverage criteria (e.g. branch-coverage, statement-coverage etc.) and code instrumentation.

However I am quite lost on how to start as I haven't found good papers or hands-on tutorials which explain the basic principles step by step. My languages of choice would be Go, Python or Java.

Are there any good resources to learn or is it possible to summarize the steps needed to implement such a tool?