What are the different symbols and their meanings that are used in Islamic baptism?

There is no "baptism" in Islam. The Word itself is a Christian Word which means, "immersion" and refers to one entering the Christian church/faith. Islam asks that to become a Muslim, one must only recite the "shahaddah" or "testament" which states: "I testify that there is no god but God and Muhammad is the apostle of God". This is similar to the Protestant concept of "asking Jesus into your heart" to become a Christian. This is the only way to become a Muslim and once a person recites this, usually in Arabic, and their own spoken language, they are considered part of the "Ummah", or community.