Okay, I found some scripture that I think proves that spanking is wrong. You can interpret this how you want. I'll write a brief note on what I've found these to mean in my studies on spanking and child rearing.
Ephesians 6:4 says "And now a word to you fathers. Don't make your children angry by the way you treat them. Rather, bring them up with the discipline and instruction approved by the Lord."
Okay, I've studied this verse and think that this means parents are not to terrorize their children and make them angry towards the parents because of the way they were treated. What is approved by the Lord is to continually parent them because that is their responsibility given to them by the Lord. I think the Lord wants us to love our children- that is our job. One of my study Bibles says that "Children should be objects of tender, loving care." The Lord also wants us to nurture and correct our child (guide them along a godly path- again my study Bible says "Fathers and mothers who do not discipline their children are parents who are themselves undisciplined and disobedient to God's will.").
Proverbs 22:6 says "Teach your children to choose the right path; and when they are older, they will remain upon it."
Big emphasis on the word teach. Spanking is not teaching your children anything- you need to show your child respect in order to teach them respect, show your child love to teach them love, etc. And choosing the right path refers to dedicating, motivating, and instructing your children to do what God has best equipped them to do.
I don't know if anyone is still interested in this, but thought I would share some of my notes. I HATE how the Bible is misinterpreted all the time. Yes, I think you could very easily read Proverbs 13:24 to say that hitting your child is okay (even though I think it clearly is not about spanking), but I think other verses show that it's not okay to spank.