[clktmr]

- Before starting to dive into the code, take a look at it from the users point of view. Make sure you know what the code does by reading manuals and playing around with it.

- Don't try to learn domain knowledge from the code. I you need to get familiar with code of a JPEG decoder, learn how JPEG works first.

- Before reading code, make sure you can jump to definition and find references. The easiest and language agnostic way is to use ctags and grep.

- Start reading code from main() (or an API call in the case of a library) and then start to dig deeper. This way will get a feeling where the "important" code is"