If you have young children do not make ponds that they can reach. All ponds are a drownding hazard and should not be accessible to young children. IIf you or your neighbors have young children do not make ponds that they can reach. Enclose your pond with a fence that will prevent children from access any pond you make.
Fish do not like sudden changes in temperature. Most "feeder" gold fish bought at a pet shop come in a plastic bag with water in in. Put the bag with the fish and water from the pet store in your pond without opening the bag. This will allow the water in the bag to slowly reach the temperature of your pond and there by avoid shocking your fish. When enough time has passed for temperature of the water in the bag to equal the temperature of the pond open the bag and let the fish out. If you live in areas were the ground freezes you should remove your fish before the water starts to freeze and keep them in a large aquarium to winter over; again using water from your pond so as not to shock the fish. Treat fish gently and humanly.