There are no state laws that describe the techniques for preservation of cemeteries and gravestones, but there are best practices and standards to meet to assure that you are preserving the site in a way that will not eventually lead to damage.
A highly recommended print resource for finding information on cemetery preservation is A Graveyard Preservation Primer by Lynette Strangstad. In her book, you can find instructions oriented to those just starting out preserving a site. The book covers all of the aspects of cemetery preservation including surveying a cemetery, determining needs of repair and restoration, preparing a plan for a restoration project, documenting data from and about the stones, cleaning, repairing, and resetting stones.
Several organizations also exist in Indiana and the nation to help with cemetery preservation.
In Indiana, there is the Indiana Pioneer Cemetery Restoration Project, a grassroots organization with the goal of preserving, protecting, and respecting every graveyard in the state.
The Association for Gravestone Studies was founded in 1977 to further the study and preservation of gravestones. AGS is an international organization with an interest in gravemarkers of all periods and styles. Through its publications, conferences, workshops and exhibits, AGS promotes the study of gravestones from historical and artistic perspectives, expands public awareness of the significance of historic gravemarkers, and encourages individuals and groups to record and preserve gravestones. At every opportunity, AGS cooperates with groups that have similar interests.
National Center for Preservation Technology and Training NCPTT advances the application of science and technology to historic preservation. Working in the fields of archaeology, architecture, landscape architecture and materials conservation, the Center accomplishes its mission through training, education, research, technology transfer and partnerships. They offer various resources materials related to the preservation of cemeteries.
The National Trust for Historic Preservation has a booklet titled Preservation of Historic Burial Grounds by Lynette Strangstad. To order this booklet, contact the Trust at 202/588-6296