Home use is very different from business use, if the cctv
is used to protect a business you need all the signs, to only cover areas where it is required, to have restricted access to the recordings, to supply them on request etc etc, it's all covered under the Data Protection Act 1998.
HOWEVER, if it is for home/domestic use the part 4 of the act specifically says:
Domestic purposes: (36) "Personal data processed by an individual only for the purposes of that individual's personal, family or household affairs (including recreational purposes) are exempt from the data protection principles and the provisions of Parts II and III".
Basically if it's for use at home you are exempt from all the storage and restriction rules etc. You are allowed to film the area outside your home, especially if it is to protect your property, however you must make sure that you minimise "collateral intrusion", that you only point the camera at the areas concerned. It may be that you record "innocent" passers-by but you must takes steps to minimise this by tilting the camera or using a narrow angle lens.
The only real problem is if you use the camera to point directly onto (or into) someones property (without their permission, neighbours are sometimes quite happy for you to cover their driveway/car as well). This is covered by the Human Rights Act 1998. Article 8: "The Right to Respect for Private and Family Life, Home and Correspondence"
The Human Rights Act is over and above other laws so be aware of this one, and don't go pointing it in someones bedroom
Oh yes, a sign, businesses have to have them with details of who is recording etc, for home use (legally) you are meant to put them up unless the camera is "covert" and is being used as a "last resort" to obtain evidence, but if you have a decent image of someone doing something they shouldn't it's very hard for them to come back with the excuse "..well if they'd have had a sign up saying they had cctv
I wouldn't have torn off their car aerial"...."So you're admiting you broke the aerial off then"......"...err...bugger".