CCtv cameras can be simple to install though this depends on how complex the system is, the camera has a power system and also an arial output and input.
In short a few wires, this can be connected either to a dedicated monitor or channeled through you TV, and viewed on your AV channel. more than one camera and you are looking at a switch box unit to convert the signal and switch between cameras.
If its a box standard system it should not take long to setup though as I dont reside in England I'm not upto date on a price to be installed, it should be simple and straight forwd though dont let someone tell you otherwise unless you have a muliti camera unit that you are applying to an office block.
If you buy CCTV Cameras just for personal use, kindly suggest to use USB Port DVR BOX for installation. (supports 1 to 4 cameras ) . As it costs much lower and operated easy.
USB DVR BOX is designed with USB Port for your PC. Simply connect it with the camera and your PC, (with approved internet protocol ) will help you control it easily (even could control from internet when you are not home)
I've just purchased a colour camera with sound, mic and nightvision (nightvision is not to great but daytime picture is superb) from aldi, cost £30 follow the link for camera spec HomeNetProducts.co.uk - Admin Fitted in about an hour.
Almost every small business shops and big households got them and yes, they are very easy to install. Just be sure to ask for the right type of CCTV surveillance when you shop for it in electronic/security device stores. I don't think there's a need for an electrician to put it up for you. But maybe it would cost around 20-30 bucks.