A: Islam is the second largest religion in the world and is still growing today. The founder of Islam is Muhammad and is know as the last prophet of god. The religion was founded near Mecca in the Arabian Peninsula of the Middle east. Islam was developed from both Christianity and Judaism, Allah is the name of not the Islamic god but instead the general term for god in Arabic. Christianity and Islam were both born from the Jewish tradition. The Christians have the Bible while Islams have the Quran.
B: The holy book of Islam is the Quran which is the central religious book of Islam. The Islamic place of worship is called the mosque. The Imam is the the known leadership position in Islam. It refers to one who leads worship and gives advice to citizens in the community.
C: An Islamic beliefs can be anyone of these and is usually one of them. There are Sunni Muslims which is the most popular type, the next is Shi 'ite Muslims which is the next popular but only consists of 10% to 16%. Sufis are the Islamic mystics, and last are the Baha'is and Ahmadiyyas, they are the 19 century version of the first two.