Derived from the root s.l.m, the verb " 'ASLAMA " in context i.e embraced Islam, means roughly: "attained internal and external peace through the RIGHT SUBMISSION to the Creator."
Historically, Islam was revealed to the prophet Muhammad (peace be upon him and upon all prophets) early in the 7th century A.D (610, if my memory is sound). The essence of Islam was conveyed by the previous prophets including, but not limited to, Ibrahim (Abraham), Muusaa (Moses) and Iisaa (Jesus) - peace be upon them. The message that prophet Muhammad (pbuh) received and conveyed has the details and finalization of that essence: It is final, he is the seal of prophets, the message of Islam is well documented and within the reach of all.
The backbone of the mess age of Islam is preserved intact and as revealed in the QUR'AAN which is the word of GOD, the CREATOR, SUSTAINER, ... THE ONE AND ONLY. Prophet Muhammad received God's word (the Qur'aan) via the Angel Jibriil (Gabriel) over a number of years. It was written, memorized by many and translated into practical actions by the prophet and his companions.
So, the prophet Muhammad was a messanger who delivered the message of Islam as God sent it to him via the Angel Gabriel (peace be with him) who also,as we - Muslims - believe conveyed the previous messages. The prophet Muhammad is widely quoted by orientalists (and those who happen to pick their work) as the FOUNDER of Islam - and worse than that, those who adhere to the teachings of Islam , the MUSLIMS, are referred to as Mohammedans, followers of Mohammedanism!!!!!!!!!!!!!
Of course, this could indicate that we worship Muhammad instead of God, which is as untrue as it is "offensive". Muhammad (pbuh) was the best example of a MUSLIM and his teachings - explana tions and implimentations of the Qur'aanic teachings - are among our sources of knowledge about Islam after the Qur'aan. The prophet Muhammad was known for his noble personality before the commencement of the message of Islam, but was just another human being - was never worshiped or held divine as implied by the term "Mohammedanism". We - Muslims - worship, and seek help from, Allaah (Arabic for God, the ONE AND ONLY).
Ok, this is growing in size and requires a larger size envelope, but it is worth mentioning that the Qur'aan is the eternal miracle as far as Islam is concerned: It's a miracle in both text and content. It was and is still memorized from cover to cover by thousands. Also, I should point out briefly that "freedom of expression" was not for granted in the ignorant Arabia then (of course, not today as well!) and the early Muslims suffered torture, sanctions, and were called lunatics etc.etc.
Now, what does Islam teach? It is a complete, comprehensive and FOR ALL way of life. It raises the st atus of the human being and liberates him/her from all kinds of bondages: from slavery to one another or to one's desire. It establishes the ultimate equality before the one and only sovereign above all: God, the almighty regardless of race, color, country of origin and so on. It establishes Piety as a criterion of excellence. It liberates the mind from all kinds of nonsense and transforms the believer into an independent and open-minded person; one who reasons rather than inherits (or hires her/his brain).
In a nutshell, Islam has 5 Pillars (actions translating the belief) which are to declare your faith by uttering that one bears witness to the oneness of Allaah (God) and the prophethood of His messanger Muhammad (pbuh), does the 5 daily prayers, gives charity (zakaah), fasts during the month of Ramadhaan and performs pilgrimage to the first House of God (in Makkah) if one affords it.
There is the heartly side of course which is to believe in Allaah, Angels, Revealed Books (all of them), the Prophets ( all of them), the Day of Judgement and I can't translate the last one accurately, but is referred to as the pre-destiny i.e. that you can't reverse the will of Allaah in matters where you have no choice (this is a very rough approximation).
Islam, being a comprehensive code of life, does not seperate material from spirit (i.e there is no religion and state). The Muslim community has the duty to enjoin good and discourage evil, convey the message of Islam in the best manner but not to force it down the throats of others (and practising on their own as well, thus setting a good example). The Muslim population is around 1.3 billions according to the latest estimates and are all over the globe.
I hope this helps as a starting point. Insha'a Allaah (God willing), you'll find more details on this site, so please stop by again!