If they are still very young they should adapt fine. If they have been with only you / family for a longer period of time, you may want to bring them for a couple of hours at a time for the first week or so to get them used to the new environment.
First, visit so you are comfortable with the facility. Then visit several times with your child so that they are familiar with the caregiver and other children. On the first days there, have a long time where you and the child are both there before you leave.
The best way to help your baby in their first daycare experience is for YOU to be calm. They pick up if you are apprehensive and will mirror that. If they have a special blanket or toy try to leave that with them, it's something they recognize.
If you are comfortable with the daycare, then it's just a matter of you handing the infant over to the caregiver to hold, while you say goodbye to them. Babies can sense if you are stressed about the situation, so try to relax.
I would introduce them to it by taking the child to the daycare for an hour or so in the begaining and building it up to a full day. Depending on how often the child needed to go I would build it up from there.