I think the best approach is to follow the mapping instructions for a [school][1]:
- tag the whole area as [amenity=place\_of\_worship][2] and add [name][3], [religion][4] [address][4], [religion][5] and [denomination][5] [denomination][6] if known
- tag the actual church building as [building=church][6] [building=church][7] and add [entrances][7] [entrances][8] if known
- add a [parking area][8] area][9] if present
- some churches also have a local [grave_yard][9]
[grave_yard][10]
[1]: http://wiki.openstreetmap.org/wiki/Tag:amenity%3Dschool
[2]: http://wiki.openstreetmap.org/wiki/Tag:amenity%3Dplace_of_worship
[3]: http://wiki.openstreetmap.org/wiki/Key:name
[4]: http://wiki.openstreetmap.org/wiki/Key:addr
[5]: http://wiki.openstreetmap.org/wiki/Key:religion
[5]: [6]: http://wiki.openstreetmap.org/wiki/Key:denomination
[6]: [7]: http://wiki.openstreetmap.org/wiki/Tag:building%3Dchurch
[7]: [8]: http://wiki.openstreetmap.org/wiki/Key:entrance
[8]: [9]: http://wiki.openstreetmap.org/wiki/Tag:amenity%3Dparking
[9]: [10]: http://wiki.openstreetmap.org/wiki/Tag:amenity%3Dgrave_yard
