What do resturants do for MSDS sheets?

In the United States: Yes. OSHA requires restaurants (and any other work place with potentially hazardous materials, like factories) to make MSDS available to employees, for potentially harmful substances that are handled in the work place. As for the other countries, I do know they have other agencies similar to OSHA that require MSDS, but the sheets may look different and have different requirements compared to the U.S.

Employers and Human Resource departments usually acquire MSDS from the suppliers and are country-specific. You can also acquire MSDS from the web: http://www.msds.com/.

From personal experience working in fast food, usually MSDS came in with the cases of cleaning supplies that we ordered. The only time our suppliers would send them was if it had been updated, or if it was our first time ordering supplies from them. Once a year management would go through the binders and check to see if everything was up to date. Usually the last revision or last edit date was posted on each sheet.