Respect the Departed:
Just as you need to treat people in this field with repect, you need to treat the dead with respect as well. Most paranormal researchers always start an EVP session by asking if you can record them. Although you're not going to hear an answer right away, it is still polite to ask first. You are, afterall, asking their assistance in your investigation. Do not step on graves or destroy tombstones. This is just wrong, and if you're the type to do this, you have no business conducting investigations.
Getting Paid:
Paranormal researchers do not charge for services. Charging is considered unethical because you already have a fair trade. You get to conduct an investigation and get evidence to study while the homeowner/business owner gets a chance to validate his experiences. There are some paranormal researchers who will try to charge for an investigation or cleansing. Steer clear of these, as they are usually scams. The only acceptable form of payment is if the owner offers to give you a donation. You should never demand a donation or strike an attitude if you are not given one.
Cleansing a House:
This is best left to professionals. Do not attempt to clean a house if you are not familiar with the practices. For this reason many paranormal researchers may hire a "man of the cloth" or other selected religous person. If you do not have such a person with you and are speakng with the owner of the property, let them know beforehand that you do not cleanse houses.
Debunking:
Many teams have researchers who are confident that every curtain that blows and a/c that thumps is paranormal phenonmenon. They not-so coincidentally seem to find ghosts in every house. However, there are so many things in a house that can cause something to seem paranormal. There are camera issues that can make vortexes out of slow camera shutters. Loose wires in a house can even cause hallucinations! For this reason it is always best to try and rule out any normal rational reasons for evidence or experiences. For pictures, it's best to know or have a photographer with experience in camera effects on your team. It's also a good idea to check the year of the house and bring an EMF meter with you to see if loose wires may be what's causing the home owner to see apparitions.
This is important because becoming a reputable paranormal research team means presenting evidence that isn't super easy to debunk by other paranomal investigators. You will appear uneducated and unprofessional if you aren't aware of simple errors in your evidence. This is also part of educating yourself.
Do not trespass on private property! Most buildings and land may look abandoned, but the property is owned by someone. A fun night of investigating can get you into trouble and possibly land you in jail!