What you need to decide is how you will be using the camera, what environmental conditions it will be used in, and what video quality you expect from it. The answers to these questions will help you select the appropriate camera. Two main specifications to look for in a surveillance camera are the lux light sensitivity rating and the lines of resolution it can provide. The number of lines of resolution indicates the detail quality of the video signal provided by the camera. Most TVs and VCRs have a resolution of under 300 lines.
Higher resolution makes it easier to distinguish fine details and recognize people from a distance.
The lux rating is the amount of light required to obtain a reasonable image. One lux is approximately the light from one candle. If you will be monitoring in low light conditions, then look for a camera that has under 1 lux rating. Cameras are available with lux ratings as low as .05 lux. Since there are so many different possible features to a camera, we can't begin to recommend one.