Baptism

The Greek word for baptism is baptizo. The definition is: to be immersed to be buried in, to be sunken as a ship, to dip, to be put under. The Bible does speak of a spiritual baptism that is God’s part. Our part is the physical baptism in water by immersion.
Why Should I Be Baptized?
To follow the example set by Christ.

At that time Jesus came from Nazareth in Galilee and was baptized by John in the Jordan (Mark 1:9)
Who Should Be Baptized?
Those who believe and have repented.

He said to them, “Go into all the world and preach the good news to all creation. Whoever believes and is baptized will be saved, but whoever does not believe will be condemned.” (Mark 16:15-16)
When Should I Be Baptized?
As soon as you possibly can!

Those who accepted his message were baptized, and about three thousand were added to their number that day. (Acts 2:41)