At 12 weeks of age, the chicks that we still had (4 of them were rehomed) found their cage set up in the enclosed section of our coop (just like our rooster was set up when he was first introduced to the girls). While we set that up, the kids watched the chicks play in the baby-gated area, and then loved on them a bit.
We put up a section of plastic on the western side of the coop that was directly behind their cage to help protect from the elements (eventually it has to rain, right?), and a bit of cardboard on the one side to help them be able to hide from the girls if they felt nervous before the established flock was let out in the morning.
I have let the established flock out to free-range and opened up the door for the chicks to explore, but they don't want to venture too far away yet. Soon they will be integrated with the rest of the flock! They aren't really looking like chicks anymore, though. They look so grown up!
Disclaimer: Thoughts of Fluff is responsible for the content of this post. All opinions are my own and may differ from those of your own.