The best cemeteries to work are ones that are neglected. The same is true for particular graves. Spirits that have been neglected are generally more willing to offer help in exchange for attention. This attention can be offering tobacco, liquor, money, or even mass/prayer.
The cemetery has its own rules and magic. It is best to be introduced to the cemetery by an elder of a tradition, however, that isn't always possible nowadays. Because I know people will attempt things that are ill advised I'm going to offer some simple basic protocols:
The first guardian when you approach a cemetery is at the gates. Sometimes the "gates" are nothing more than a sign or demarcation at the road. Whatever the situation this area is to be treated as a spirit. I recommend simply announcing yourself to the Master of the Gates. As you do, sprinkle some liquor and ask for permission to enter.
At this point wait for a sign or signal that the spirit has acknowledged you and will permit your entry. At any sign of hostility immediately abandon the idea of entry for the day, pour liquor, and leave.
If you gain entry the next is identifying the Master of the Cemetery. This spirit is generally the oldest male grave in the cemetery. In very old cemeteries this grave my be impossible to find, instead one should look for the highest cross, flagpole, or some grave/crypt of prominence. There should be a sort of magnetism of the area, as this is the spirit that is acting as chief in that cemetery. Some sign of life should be noted as well such as an insect or animal. Again this spirit should be acknowledged and offered liquor, tobacco, and/or money.
State your business clearly to this spirit. Say why you are there and what payment you will offer for the help given. The spirit may take on the task for himself or direct you to a grave of a willing spirit. If you are directed to another spirit that spirit make be acknowledged similarly as the Master of the Gates and Master of the Cemetery. You should also make clear that you were directed by the previously encountered spirits.
From this point I would recommend doing your work at that grave. Taking home a spirit without proper experience and guidance can quickly get out of hand. Instead light your candles and do your work, and tell the spirit what you will pay for success. Generally, having a mass for the spirit said will hasten results and also be considered payment.
When you are finished head straight back to the gates. Drop some change in both sides of the gates and say, "I pay you," as you exit.
You will do the same at the first crossroad you encounter.
This guide is not all encompassing as every cemetery is unique. It is recommended that you dress appropriately when you go: wear white or denim. Act respectfully and be concise in your words. When you return home, before entering, make sure to clean the bottoms of your shoes; if wearing sandals clean your toenails. Finally, bathe in a simple bath if bitter herbs to remove any clinging energies.
The cemetery has very real power that goes far beyond doing baleful acts. I have healed people (including myself) almost instantaneously in the cemetery. I've also created good fortune for myself by tending to neglected cemeteries in very simple ways. Respect goes very far with the dead and they can be very quick to please.
*I posted this merely to be informative in a sea of misinformation. I bear no responsibility for the misuse of this information and strongly encourage that you find a real teacher to work with.*