What's required to become a Christian?
If you believe that:
and you are willing to:
then you are ready to become a Christian.
How do I become a Christian?
See Steps to Peace with God.
All you need to do is to pray something like this: "Lord Jesus, I know that I am a sinner and need Your forgiveness.
I believe that You died for my sins. I want to turn from my sins. I now invite You to come into my heart
and life. I want to trust and follow You as Lord and Savior."
What do I do now?
Contact other Christians in your area. If you have a friend who is a devout Christian (perhaps they've been talking to you about Christianity), get in touch with them and tell them about your decision. Also, feel free to contact me with any questions or concerns you have (or just let me know that you became a Christian).
One important thing to do is to be baptized, as an outward symbol of your choosing to follow Jesus Christ. (See Mt 28:18-20, Acts 2:38, 10:47-48.)
Another important thing you should do is find a healthy church in your area. A healthy church is focused on God, is welcoming to newcomers, and has a growing congregation, not a stagnant one. The denomination, or whether it's Protestant or Catholic, is not as important as the church's teaching. If you don't know where to start, I recommend a non-denominational Protestant church (these can be found by looking in the directories for "inter-denominational," "independent" or "non-denominational" churches). In any case, check the church's statement of faith or talk to the pastor/priest and make sure they believe that the Bible is the inerrant word of God and that the church's main focus is on worshiping God and fostering spiritual growth.
Directories of churches: