Litigation, arbitration and mediation are the three most common ways to resolve disputes.
Small claims court is a good way to deal with smaller cases (usually $1,000 to $5,000, depending upon the state).
If you want to litigate a larger case, it is generally a good idea to hire a lawyer, because the rules of court are complex and critical mistakes are often made by those untrained.
Arbitration involves the appointment of a person, usually a lawyer or other professional, to act as the judge. Arbitration can work well for people representing themselves, as there are fewer rules and arbitrators generally will forgive technical defects.
Mediation is a structured meeting where people and companies try to resolve their differences. This can be a low-cost way to try to settle a case before substantial sums are spent on a lawsuit.