The first and most important precaution to take before searching for dinosaur fossils (or any other fossils) is to make sure you have permission to search the area. In addition, verify that you can collect and keep any specimens you find on the land. Without permission, you may be arrested and charged with trespassing, destruction of property, or even theft. It is much easier to ask permission beforehand than to deal with legal proceedings, arrest, or jail-time afterwards. Always find out what person, organization, or government agency owns the property.