It's amazing that nearly every single command line tool comes with a manual via man , but navigating the man output can be sometimes a little confusing, plus it can be daunting given all the technical information that's included in the manual output.
htop is an improvement on both regular top and crappy-mac top. Lots of colour coding, keyboard bindings and different views which have helped me in the past to understand which processes belong to which.
Handy key bindings include: