The instructions say that once the seedlings have developed their first "true leaves", I should put them outside during the day to harden them off. All the tomatoes are ready for this move, but not all the peppers. In fact, some of the peppers are just now starting to germinate. I may start putting them outside for awhile anyhow.
So far, all the little plants seem to be doing well. They look a bit leggy, but that's to be expected.