Breakout rooms are a very powerful collaborative tool that can be used in your online classroom. Lachlan Kalache thoroughly describes the use of breakout rooms in these 2 videos.
In part 1, Lachlan describes how breakout rooms can be useful, when to use them and how to set them up using a breakout layout.
In part 2, Lachlan describes specific strategies for breakout rooms and content to have ready.
A great resource for a newbie even if this is targeted at advanced skills.