What are the qualifications for baptism?

A person must believe that Jesus Christ is the Son of God and the gospel news that He is the only Savior from sin (Mark 16:15-16; Acts 8:37; 2:38). He must repudiate his sins and turn from them to live a holy life according to the terms of the Bible (Acts 17:30; 20:21; 26:20). His conscience must be convinced of the truth of the gospel so that he is free from guilt for sin and fear of condemnation (I Pet 3:21). Since baptism is the first act of obedience to Jesus Christ and living a new life for Him, a person must understand the nature and costs of true discipleship.

For further study about baptism:

Catechism about baptism: Catechism.
All the Bible teaches about baptism: Baptism.