When can I put them outside?
This depends on the weather. If it is warm, they can probably venture outside during the warmer part of the day at one week of age.
Keep them in a small area so they can get back to a warm, protected area if they need.
They need to be protected from rain until they are about six weeks of age when they are almost completely feathered.
If the weather is not warm, you may need to keep them confined until they are six to seven weeks of age. The best thing is to watch them.
If they appear cold or huddle together, bring them back inside.