When do you start disciplining your child?

Over the long weekend a few friends and I got into the discussion about when do you start disciplining your child. When Alex was a baby I read every parenting baby book out there about this topic. I was so afraid I was going to make mistakes! Ha ha!! In my opinion, a child under the age of one does not understand being spanked, swatted, etc. I always redirected Alex and it was not until he was well over one year of age that I started to swat his little hand and say "no". I NEVER spanked him. In my opinion a baby does not understand being spanked and certainly doesn't grasp the idea of time out. It was very interesting to get every one's opinion as we chatted by the camp fire. The main reason I started the conversation is because we have a very young lady in our family who has a baby who just turned one. She is having some issues (in my opinion of course) with the whole parenting thing. It's only to be expected though considering she is just a child herself. We try to guide her in the right direction, but I have to say it's hard. So I started a poll to see what you guys think. I just love doing these polls so please take the time to vote and/or leave me a comment on what you think.