1) Shoes: If you see a pile of shoes at the door, it means that this family takes off their shoes inside their home, so plan to do the same. Shoes are considered dirty.
2) Physical Greeting: Woman to woman: A hug or three kisses are fine. Man to man: A handshake is a common greeting. Man to woman: Do not shake hands or have any physical contact, unless the woman extends her hand. Woman to man: Do not extend your hand to shake a man's hand unless he does that first. Between genders it is common to put your right hand on your chest as you greet.
3) Verbal Greeting: The preferred greeting among Muslims is assalam alaikum (“peace be upon you”), which is answered with wa alaikum assalam. Christians use marhaba (mar = God, haba = is love). Watch a lesson here.
4) Hospitality: This is really important. Do not refuse Arab hospitality, as this is the easiest way to create a barrier.
5) Prayer: In Islam there is ritual prayer (salat) and there is supplication (dua), which is closer to biblical prayer.
6) Church invitation: Should I invite my family to my church? Not unless they ask you to do so. Otherwise, don't. Chances are that they may think that your support is tied to them either joining your church or converting and it will likely make them suspicious or feel manipulated. If they request spiritual support, a small group is a better option. Besides, the church setting is really strange for Muslims: music, no gender segregation, the fact that we sit in chairs/pews when at the mosque there is only a carpet, women's clothing, and more.