Skip meals for a day or two and sleep in a graveyard wearing as little clothing as you safely can. None at all, ideally. Set up recording equipment at an angle that doesn't capture schlong, have a diary to write down anything that you remember from your dreams in detail (you will dream), and you're good to go. If you get video of something, it must not make a sound. If you find hear sound of something, it must not be seen. Anything "ghostly" that you can both see and hear is a hoax or a fraud, or simply has an unexplored explanation.
Gravekeepers are emphatically hostile to such an act due to ingrained Judeochristian views on it as immutable sin, dangerous, and an affront to God, but most people are not consciously aware of why, so you can probably get away with it if you prepare well enough. Just do be aware that in this day and age, even if they aren't used to "investigator traffic" anymore, they are intimately familiar with graverobbers.
As far as what to bring to any site you think might be haunted in general, >>287 has the right of it. Bodily worries before fun spooky hijinks. "Hiking supplies" are a must. For the rest and to varying levels of difficulty and lunacy, bring some non-hallucinogenic incense, and the cleaned bone of a small animal. Incense is supposed to make an area "unclean," and therefore easier for spirits to inhabit. By putting the bone of a small animal in your mouth, you forfeit the sanctity of the mouth, allowing a spirit to talk through it. In theory, I mean, I've never tried it and it's a bit too far out there for my tastes. Chucking dead animal in your mouth and giving speeches probably sounded like a better idea before modern medicine.