If you're an #opensource maintainer seeking a good task to give a less-skilled new contributor, ask them to do a discovery report on the project, such as:
Starting from scratch, try to get a local installation up and running, and note how long it took.
Take an hour to explore our documentation and fora, and tell us your impressions.
Given a demo install, try these common user tasks.
Examples:
https://diff.wikimedia.org/2014/03/25/seeing-through-the-eyes-of-new-technical-contributors/
http://blog.linuxgrrl.com/2014/03/25/hyperkitty-at-the-0th-spinachcon/
https://blog.openhatch.org/2014/spinachcon-zero-a-huge-success/