Good recording equipment is essential, so tape recorders and Dictaphones should be used. The higher the quality of equipment the better the chance that of future analysis of any evidence recorded. Most researchers use infrared cameras during their investigations. These are particularly good for picking up mists and light anomalies.
High-end equipment such as radiation detectors and thermocameras can also be purchased but could cost huge amounts of money. The famous ghost hunter Peter Greenwood once commented that he had seen ghost hunters with cars full of equipment and yet it is the man with just a tape recorder that gets the evidence. Thus is the nature of the paranormal!
P/S: In 2005 GhostRadar was launched and claims to be very accurate. It uses the body’s chemicals and senses to detect ghosts.