Pinpoint what type of injury occurred. If you slipped and fell on an ice-ridden sidewalk, this is a slip-and-fall injury. But, the legal term is a negligent act and you are claiming that the state failed to maintain the sidewalk.
Determine who caused the injury. Did a person do it or are you saying the government had a policy to do something bad to you. Was it the negligence of the city or the negligence of one person acting outside of his job capacity? Sue the right person.
Look at the statute. A statute is a law that the legislature has enacted. Generally a local government is immune from lawsuits. You can't easily sue a city. Therefore a state statute must give you that right. Check the state legislature's website for the state code. Inside the code search the term "immunity." Read down the list and see if your injury is there.
Look through the state statutes for special rules. There are several statutes for one issue. The first statute might seem to say, "No, you can't sue a city," while the next says you can. Look for the special rules. A special rule might send you to another statute telling you what to do if you were injured on public property. Follow the statute trail until you have narrowed the search and discovered all the laws surrounding your situation.
Limit the compensation you are seeking. Check the statute for a maximum dollar amount of your lawsuit. Cities were claiming that they would not be able to provide vital public services because of the threat of bankruptcy from lawsuits. The legislature has put a cap on how much you can sue for. Do not sue for more than the statute allows.
File a claim with the court within the statute of limitations. This is another statute you will need to keep in mind. The statute of limitations places a time limit on how long you have to sue. Meet the deadlines and all the other statutory requirements to sue a city.