RFID Shed Alarm With Magnetic Reed Switch. Advice Needed.

Hi Guys, my first post on here so please bear with me.

I am new to arduino and my first impressions are that I totally love it. I have been making simple projects mainly from books but I wanted to make something a bit more useful.

I have a shed at the bottom of my garden and I wanted to make an alarm for it. To make this post easier to read I will number what I want the alarm to do in order.

  1. Be powered up all the time. I will be running of 6v sealed lead acid battery connected to solar panel on shed roof.
  2. When a suitable RFID card is scanned I want this to either arm or disarm the alarm.
  3. When the alarm is armed I want a small buzzer to sound for 15 seconds to give me enough time to leave the shed and lock the door.
  4. When the door is locked I want the alarm to be activated.
  5. When the door is opened I want the same buzzer to sound for 15 seconds before the main siren is sounded or the same RFID card is scanned (Disabling the alarm).

To make this a whole lot complicated, I want to have 16,2 LCD to give out information regarding the status of the alarm. For Example "Alarm Activated" or "Alarm Disabled" "Door Open" etc etc.

I used to be pretty good at electronics but I am totally new to micro-controllers but I know how to follow shematics, resistor colour codes etc etc.

I have been at this for a couple of days now and I just can't figure how to connect everything up let alone code it. So I was wondering if anyone could help me please. I have tried googling it and nothing at all comes up to suit my needs nor does anything I can modify.

If I could get a schematic and/or code to get me heading in the right direction, I will be able to modify the code to suit my needs exactly.

I already have an Arduino UNO, RC522 RFID Reader, 16,2 LCD, Normally Open Reed Swith, Siren, Buzzer, Case, Battery, LED's, Relays, Solar Panel and a whole bunch of more stuff.

I just need someone to help make this happen!

Thanks
Rob

I would love to implement this http://www.instructables.com/id/Arduino-RC522-RFID-Door-Unlock/?ALLSTEPS into my project, would make programming cards a whole lot easier!