Looking for comprehensive handling guidelines? Well look no further. The National Park Service, of the U.S. Department of Interior, has produced very thorough and comprehensive documents to assist with dealing with their collections. Most of the information is not of great relevance to most Art Techs except for chapter 6 in the NPS Museum Handbook, Part I: Museum Collections which is a great manual for the handling of art and artefacts. It outlines everything you need to know about manual handling, giving clear and concise guidelines which can be easily adopted by all art technicians. It also has a very brief overview of packing and shipping.

NPS Museum Handbook, Part I: Museum Collections. Chapter 6: Handling, Packing, and Shipping http://www.nps.gov/museum/publications/MHI/CHAP6.pdf

You can find more at https://www.nps.gov/museum/publications/handbook.html