I'm surprised by the quality of Wikipedia's article on Eastern Orthodoxy, and the lack of the hostility toward Christianity that can be found in other Wiki entries.
"The Eastern Orthodox Church is a Christian body that encompasses national jurisdictions such as the Greek Orthodox, Russian Orthodox and other Churches (see Eastern Orthodox Church organization). It identifies its origins in the original undivided Christian community founded by Jesus for salvation, with its traditions first established by the Twelve Apostles at the time of Pentecost and maintained through unbroken Apostolic Succession."http://en.wikipedia.org/wiki/Byzantine_church
In the first paragraph alone, one can find practically all that the unconverted would need to know about the Orthodox Church.