I need to learn more about Sunni Muslims!?

When Sunnis go to mosque, what do they call their leader? For example, in Catholicism it's a priest. What are the rituals done in a Sunni mosque? Do men and women sit separately? What about the kids? How are prayers done. Does the leader give a sermon? Is special types of food served? I'm mainly concerned with Sunni's living in north America. Please tell me anything you know about Sunni Islam practices. Thanks.