I know nothing whatsoever about setting up a CCTv camera but I was thinking 
about getting this from aldi
http://uk.aldi.com:80/sunday_special_buys/productnl_392.html.
Could this be connected to a simple PVR to record 24/7
thanks

In answer to your question  any vcr with a scart input will work with this 
unit but you will only get 8hrs on long play with a 4hr tape also the 
quality will be poor.
24hr vcrs are available but with this camera they will be a waste of money 
as the resolution will be very poor.
At the end of the day you only get what you pay for and these type of deals 
are aimed at low resolution real time monitoring.IE you sit and watch it 
when the motion detector switches the tv over.
HTH
CJ