Dear Tricia,
You are correct to tell your son, firmly, "No Biting". And you can put him in time out. Use his crib or a playpen as the time out space. It is absolutely not too early to begin using time out. Many parents think that time out cannot be employed with such young children. In reality, it can be used and is quite effective.
Also, it really won't help to slap him. That is a disciplinary tactic that you would do well to abandon. It will only encourage your son to imitate your behavior.