In California the law requires a safety or tailgate meeting every 10 working days. There are two important things to do at these meeting.
1) Bring up a particular topic
2) Get a signature from everyone explaining that they understand the topic discusssed
The easiest way to do this is to have the meeting right before you hand out out the checks. Here is a form you can download to collect signatures
The important part is to bring up a topic and allow workers the chance to bring up their own issues. By having them sign this document it will reduce your liability by creating an environment where people can bring up safety issues which shows safety initiative and legal compliance.