When you have a new piercing, there are a lot of things that you should avoid. They either don't play nice with the healing process or they can cause damage.

Over Cleaning
This can extend the healing time for you piercing and possibly make it a more painful one.

Harsh Cleaning Solutions
These include Betadine, Hibiciens, alcohol, hydrogen peroxide, harsh soaps like Dial, as well as ointments and Bactine. The first bunch can damage the cells in the area which will extend healing times and cause improper healing. Ointments prevent air flow to the wound. This will allow moisture buildup which is one of the biggest ways an area can be become infected from. Bactine or anything with Benzalkonium Chloride are not meant for long term use.

This can be anything from friction from clothing to excessive movement of that area. There are ways to prevent these forms of "trauma" for the various different piercings that these will be probably happen a lot with.

Body Fluids
More specifically, other people's body fluids. There are numerous health risks from letting their fluids come in contact with your piercing/open wound.

This is includes everything from caffeine to alcohol to cocaine. Drugs reduce the immune system and can also cause stimulation that isn't good for a piercing.

Your healing piercing just shouldn't come in contact with open bodies of water. By open bodies of water I mean anything that other people use. This can include hot tubs, pools, lakes, ponds, rivers, etc. These can easily contain bacteria and other bad things for your piercing. There are waterproof products that are made for wounds so if you really have to, you can get one of these and go about things as normal.

Lotions and Cosmetics
Most lotions and cosmetics create a sort of seal that prevent air flow and can create an environment infections thrive for. Also, they can contain chemicals and such that are just bad for an open piercing.

The body jewelry used at the initial piercing of it should stay in until the healing is done. There are circumstances that the piercing needs to be changed. These are usually severe. This can include a bad reaction to the type of body jewelry used or and really bad infection. If you are unsure about how you may react to the type of body jewelry, try titanium. Those that tend to react to body jewelry is because of the nickel. Titanium has virtually no nickel in it. Anything less then surgical stainless really shouldn't be used for a new piercing anyways.