I found this timeline in a Reuters investigation very helpful:
https://www.reuters.com/investigates/special-report/migration/#story/28
It gave dates and headlines on what was happening in Libya. Then it provided links to stories, which you can click on if you wanted more info. If not, you can still read in chronological order what was happening and when, and how and why Gaddafi's fall led to mass chaos for migrants and Europe later on.
Anything that is simple to read is best for me. I love it if you can click on a link for more because not everyone wants to read that extra information but it's also important that it's there.