I encourage even people who "know" this program to check the whole series on the Tutorial Playlist of the FlowScape youtube channel:
https://www.youtube.com/playlist?list=PLsATq8iGZqxHGZLnMMJMWcPMzEdDAUQ0d
You should play it in order, starting with the 9mn tutorial, showing almost everything, but also do not miss seing all the other videos. Most are 1 to 3mn videos, some of them showing incredible tips and clever usage of some of the features (really, even if the video subject seems "known", you should check it out anyway! for ex: lighting show how to "build" a projector, planets shows how to import objects and modify the texture easily, etc)