Give them a question to research and find resources about. Ask them to look in places like:
Work individually or in pairs. Give them an online document to share links to materials they find. After 5-10 minutes of searching, spend another 5-10 minutes having each group show what they found. You could organize the materials into different categories or highlight materials which you think are particularly useful.
You find out where they usually go for information and what kinds of things they already know about. They get reminded that they already know about the topic and/or have places they know to look and/or colleagues who know where to look.