i setup my home system from scratch and i'm only 14 so it is not hard to do!
i have 2 cameras in our alley, one in the bike shed, one in the porch, one looking at the front gate, two looking at the road (incase anyone gets run over again, its a busy road and there have been a couple of incidents), one looking at the back gate, one looking at the back door and two monitoring the garden.
i also have two ptz's on the roof, one is so we can zoom in on the car when its parked, the other is to zoom in on the park next to us because kids always set fireworks off (this is probabky not legal but the police asked for footage, not for us to take it down)
i also have a pir and sounder in the shed, door contacts on all doors, glass smash sensors on all windows, pirs in all hallways, sounders at doors and main hallway and some vibration sensors inside some cameras (like the ones in the alley)
oh, and a sounder on the side of the shed.
if the shed gets broken into, the alarm goes off in the house and shed and alley, an auto texter (made by me) texts me and my dad that the shed alarms have activated, the cctv camera in the shed goes from recording at 0.5fps to 10fps.
the cable comes back to the house in a metal conduit pipe. if somehow it got cut, the videoloss/tamper alarm would sound all the sounders in the house, the shed would not have a hold off signal so the sounders in there would activate too! (and we get a text)
if someone throws a brick at a camera again during the day all the alarms go off and the camera that has been hit goes into alarm. if its hit during the night, only the alley sounder activates. (but we get a text)
its a pretty complex system and i am proud of it. most of the stuff in it is from ebay. most of the cameras, sounders, pirs, etc are all second hand! my cameras cost me between £20 and £45 each so second hand is what i'd reccomend!
i documented my whole system and put it on youtube but my account got terminated because someone flagged every single one of my vids. i have a new one but it needs time to grow. you can find it here:
http://www.youtube.com/user/flamesecureUK