A short list of What Every American Should Know About the Middle East.
Arabs are part of an ethnic group, not a religion. Arabs were around long before Islam, and there have been (and still are) Arab Christians and Arab Jews. In general, you're an Arab if you 1) are of Arab descent (blood), or 2) speak the main Arab language (Arabic).
A companion list of what every resident of the Middle East should know about the US might also be helpful. (via chris glas