a question about Zones

Hello,
 
I'm a new owner of an Elk M1 gold and I am starting to wire it up in my home. I've not worked with a Security panel before so I'm not sure what all to place into a Zone.  
 
I am initially thinking a wiring up one area at a time, so I guess that would be the start of a Zone.  
but can a Zone have more than one device?  I am going to start off by connecting a wired reed switch to a door so I get familiar with the different aspects of making this work.
 
My foyer area has two doors; outside and inside and then the main central hallway begins (old American four square dwelling)  Should those reed switches be in the same Zone?   or should I place the sensors into two different zones, so the triggering is more specific to the individual door?  simple wired reed switches don't have addresses, so I guess its a matter preference? 
 
and then, to go to the next step and wire in a occupancy sensor?  ok to add to an occupancy sensor in a zone with a reed switch or place it into a separate Zone? 
 
I am just trying to understand the general rules of thumb for hooking up sensors and defining Zones. 
 
Thanks.

Wire each sensor to a separate zone if you have enough. Wire in series with an EOL resistor.

Otherwise, you have a couple of options:
1. Buy an expansion module with additional wired or wireless zones.
2. Wire similar type zones (window, exterior door, motion, etc.) in series. The reason is doors are typically configured as delayed entry/exit to give you time to get to/from the keypad. Windows are not. Motion sensors are typically a follower. Interior doors do not need to be monitored. It's about perimeter protection. Study the manual for the different types of zones and how they are affected based on arming mode. Don't forget to include an EOL resistor in series.

Read Elk manual and register your panel so you can login to Elk M1 owners site to download the ElkRP2 remote programming application, firmware updates, and manuals.

To expand on what elvisimprsntr said...
 
Keep doors in separate zones from windows.  And keep motion detectors separate from the doors and windows.
 
It's common to put all the windows in each room in their own zone.  That gives you the ability to tell that it was, say a living room window that triggered the alarm, although you may not know exactly which window it was unless it is obvious that the window is open.  If you want to spend the extra money for Elk input expansion modules, you can put every window in its own zone and then know exactly which one triggered an alarm. Many people like to do it that way.  Of course, there is no reason you couldn't wire the windows from several rooms into a single zone.  It's just a question of how much granularity you want and how quick and easy it will be to track down a problem, like when the system won't arm because a window was left open.
 
Usually, each door is wired as its own zone so that you can know which door is secure, and configure different delays if necessary.
 
Motion detectors go on their own zones so they can be configured as interior zones that are bypassed when you are at home (STAY mode), but still keep the doors and windows armed for perimeter protection.   There may be some interior motion zones that you'd keep armed in places where you are unlikely to go, say in the basement at night.  So wire them to their own individual zones if you can.

And not to contradict elvisimprsntr, it is alright to put an interior door, say the one accessing your garage, on a zone.  I'd keep overhead garage doors on separate zones as well.  Interior doors can be monitored in a way that will sound the alarm if opened while Away or Vacation, but nothing happens if you open the door while armed Stay.

Thanks.  Is it ever practical to double up any senors for any Zones?  The manual talks about daisy chaining smoke detectors, so besides daisy chaining smoke detectors are there any other sensor types that can wired in series, into the same zone? i.e. two window detectors are the same type of sensor if placed in the room/zone. I can see the need to implement several expansion input modules and turn the ELK into a giant central hub. 

Combining zones can certainly be done; many times done when a series of windows exist in a single room. It really depends on the level of granularity you want. If you want to know that the left-most window in the living room is open, it needs to be wired on its own zone. However, if there are 6 windows in the room, and you only care to know that any one of them is open, you could wire them all in series with each other; which would end up saving you zones, but you lose the granularity to know specifically which one it is.

There should be a rule of thumb when applied to zones and practicality.

Doors should be their own zone.
 
Windows can be combined by whatever method you see fit.
 
Powered devices (GBD's, PIR's) should always be their own zone and never combined with perimeter devices
 
Panic buttons should be their own zone.
 
Critical condition monitoring depends on the device itself, if it's powered, it should be by itself.
 
Life safety devices are special considerations as the wiring methods of the circuits vary significantly. CO detectors can be wired together, however that changes the amount of conductors installed in the field and between devices. Same holds true with fire alarm. I do NOT agree with creating multiple zones of fire each with a single smoke detector on a simple residential panel.Smokes vs. heats is a different story.  If that sort of granularity is desired, there's other panels or devices that are better suited for the application.