Even if you don't hear anything during the hunt rewind the tape and play it back. Spirit voices have been known to be heard on tape later after review. This is referred to as, EVP, Electronic Voice Phenomena. Again, use brand new tapes when recording. Sometimes candles may be used but don't count on them staying lit.
Notebook is a good way to keep notes, records of time or a journal of events.
EMF Detectors can pick up electronic fields over different frequencies. Where there are ghosts there are usually disruptions in the electronic field. You should try to get a hold of one or more of these for all field work. As a guide line each person in your group should have one on hand. It's best to use the old fashion mercury filled, red line, thermometers.