We have lots of Muslims living in Germany (mostly Turkish), in fact in Berlin (my home town) Islam is the second biggest religion right after the Lutherans, but ahead of the Roman Catholics. We had problems with the first and second generation of Turkish immigrants (who often came from rural, backward, uneducated, feudal Turkey, after all the factories and builders recruiting the Turks during the 60s and early 70s wanted labourers to do the dirty jobs Germans didn´t want to do anymore, not PHDs, most of the loaders at CGN
are Turkish). When they had children here, they went to regular school, but there was trouble between religious parents and esp. the girls, once they reached their teens. There were stories about forced marriages, killings and fights (e.g. a German teenage boy, who dared to date a Turkish girl (and many Turkish women a very pretty), being beaten up by her brothers and herself sometimes killed if she lost virginity, for protecting the "honour of the family"). Nowadays, with the fourth generation in the making, these stories are getting rare.
Another thing is that Islam doesn´t have a central doctrine and control concerning the interpretation of the Quran as e.g. the Roman Catholic church. There are lots of different Muslim groups, some of them hating each other´s guts (Al Qaeda as Wahabites, a very fundamentalist Sunni branch, mainly based in Saudi Arabia versus the Shi´ite Muslims from Iran. They consider each other as heretics, very similar to the Protestants and Catholics during the 15th century in Europe). Osama Bin Laden might have hoped to unite ALL
Muslims under his leadership, but this will never happen. Also mainstream Islam in Turkey, Bosnia or Indonesia is completely different from the Islam preached in Saudi Arabia or Afghanistan.
For myself I like the interpretation of the Alevits, a branch of the Shi´a Muslims, found mainly in Turkey and Syria.
For them religion is a private matter, they don´t even built mosques, and since you don´t have to show your religion, just to live it, women usualy don´t wear the hijab (I talked to several members of this branch) and are getting the same education as the men. Since they believe in religion as a personal matter they are also strictly in favour of seperation of religion and government.