Nobody did Islam, so I will.

In a nutshell, there's 6 articles of faith that a person needs to believe in to be a Muslim.

1) There's only 1 God.
2) Belief in all the prophets (Adam, Moses, Abraham, Jesus, Muhammad, etc).
3) Belief in all the holy scripture (psalms, bible, torah, qur'an).
4) Belief in angels.
5) Belief in the day of judgement.
6) Belief in the predestination set by God.