I have a three year old daughter that lives in Kentucky with her mother, and I currently am married to another woman whom I have two children with and we reside in Florida. I am not allowed to see my child in Kentucky because her mother won't let me. I would like to give up my rights to her, what do I need to do?

Giving up your rights is quite straight forward.
Just head down to your local court house and ask them.
BUT signing away rights doesn't stop you having to financially support your child.

If you wanted to see your child you would only have to file for visitation in her home county. I know it wouldn't be a breeze since you don't live there, but it is another option. Then her mom would have no choice but to allow you to spend time with her. If you simply want to give up your parental rights, curlyben's answer is right. Good luck.

As noted to 100's on here every week, You can always sign your rights away, Those are the right to visit, the right to have a say in her life.

What you can't sign away is your obligation, to child support, possible health insurance and the such. Those you will have to pay even if you give up your rights, (unless a new step parent is willing to adopt the child)

What you really need to do is file contempt of court charges if she will not let you have visitation as ordered by the court. You can use the court to force her to allow you to see your child.