I had an "agreement" for years and came to realize it was better to have things formalized through the court. This way there are no misunderstandings and the courts can step in if either side waivers.

There are a few things they focus on in hearing.

1. Paternity- if either party questions it, then the court will order a dna test. The person who questions it usually pays for the test.

2. Income- you will need to gather copies of recent w-2's, income tax returns, bank statements, things like that. Each party has to verify current income.

3. Previous payments made- If retroactive support is requested and granted by the court, then any previous payments are considered into the calculation.

4. Time spent with each parent- Each state varies, but if a child spends more time with one parent, then that may be considered in the calculation. (It may be something like more than 40% of the time with one parent. )

If this is a child support hearing conducted by the state actual visitation and custody arrangements are normally not discussed.

Have your facts in order and keep your answers brief for the judge. The other party may want to sling dirt on you before the judge. They are doing it to protect themselves.
Stay strong, be courteous and you will come out ok.

After the order is signed by the judge you will have a appeal period. Again, that varies by state. Find out what yours will be, because if there are any errors in your order you want to take care of it during that time.