Remove the spark plugs and turn the engine over by hand is a good start. This will push any water out of the cylinders. If water did get in there and you don't remove the plugs, you could bend a connecting rod, blow a gasket, or even do valve train damage to it. Also, if it does have water in it you will want to try to clean out the cylinders with the plugs out to get any debris out too. Once you get that done you will want to change the oil. If it had a lot of water in it, drive it 500 miles after the oil change and do it again to be safe.