The hot water should be on the left side and the cold on the right. This is a convention throughout North America, and it applies to single lever as well as dual faucet arrangements.
Where this is reversed, people can be surprised at best or scalded at worst if they're expecting to get cold water and they get hot.
There is another issue related to faucet conventions that sometimes frustrates people. There is no requirement for this, but compression-type faucets typically open counterclockwise and close clockwise. The modern cartridge faucets with a quarter turn to open and close do not always follow this convention. Most of the systems can be rearranged so that they do follow this convention. One convention with lever-operated, quarter-turn faucets is that the handles for the hot and cold are both parallel to the front of the sink and pointing away from each other when they are closed. The handles point toward the operator when they are open. This means that the hot usually turns through 90 degrees in a counterclockwise fashion and the cold turns through 90 degrees in a clockwise fashion to open. Closing these valves means pushing them back into their parallel position. The hot lever gets turned clockwise and the cold lever gets turned counterclockwise. This can confuse people if they are used to the compression faucet system of clockwise to close on all faucets. As long as the hot is on the left and the cold is on the right, there is no danger if the faucet arrangement isn't intuitive in a clockwise or counterclockwise direction.