Note that this is somewhat limited due to being free; for more and better stock images you will want a plugin that accesses paid services like ‘Getty Images’. Also I have not yet researched this fully as I usually roll my own images.
Select ‘Install’ and then ‘Activate’.
Also ‘Activate auto-updates’
To use it, go to ‘Plugins’ and under ‘Download Free Images’, select ‘See Library’.
Once you’ve found an image you want select ‘Download’.