What are the main rooms in a church?

It depends on the type of church, but if you are talking about a traditional church layout, it has the following parts

1. The Nave is the main body of the church, where the congragation sit.

2. The altar stands at the front of the church, in an area called the sanctuary. The part of the church building which contains the sanctuary is called the chancel.

3. In some of the larger churches, there is an area between the nave and the chancel, called the choir.

4. Some churches are built in the shape of a cross, with two short side-arms. These side arms are called transepts.

5. Some churches will have small side-chapels. They may also have a small room or side chapel called a baptistry, where the font is kept.

6. Some churches will have a basement room, called a crypt.

The picture at this link gives a typical example of a church plan, with the main areas labelled.

http://upload.wikimedia.org/wikipedia/commons/7/7c/Layout_plan_of_All_Saints%27_Church,_Newchurch.gif

The Sassy Room
The Lassy Room
The Little Boys Room
and Father Tuckin's Play Area

You all forgot the bathroom !!!

nave '
sacristy
store room
chapel
confessional
tabernacle alcove

The vestibule is the front of the church.
The sanctuary is where the worship rite takes place
In some churches there is also a side chapel and a place for the priest/minister to prepare for the service.

place where they talk