Steps

1. First, figure out whether you really need to get the law involved. Try hard to resolve the dispute without the aid of the courts first, because it'll be much faster and less expensive.
2. If the party who hurt you has given you money or other compensation in exchange for your signature on a document, review the document you signed. You might have already signed a promise not to sue them, in which case you are done and can go no further. Ask a lawyer to make sure, but in most cases, if you accept a settlement, you can't sue. So make sure any settlement you accept is totally satisfactory before you take it!
3. Consider hiring a mediator. There are professionals who can help you resolve a dispute without needing to file a suit. Many mediators were once lawyers or judges themselves. Their services are not cheap, but they cost less than a lawsuit will.
4. Consult or hire an attorney before you file the suit. The attorney can advise you on how to proceed. There are organizations such as Legal Aid that offer legal help, if you cannot afford an attorney. Some attorneys may represent you "pro bono" (at no charge).
5. If you do not wish to hire an attorney, you may file the lawsuit pro-se. This usually requires typing the lawsuit in the typical format and submitting it to the clerk of courts. Note that lawsuit paperwork usually has a case or civil action number to the right of the parties listed. This should be included on other filings, such as motions. For the initial filing, type "Case no:" followed by blank space; as seen in the example, it will be stamped or written in when the case is assigned to a judge.
6. If you want to file pro-se and are seeking a small amount of money, file the lawsuit in small claims court. Most small claims courts (or circuit courts, depending on the jurisdiction) are for disputes with a low monetary amount (usually less than $5,000)
7. If you are sure you need to file a lawsuit and the lawyer agrees, estimate the size of the stakes. If it's a matter of property worth less than a certain amount (depending on the region, something like $500 or less), then you will file the suit in small claims court. If it's a dispute over child custody, a personal injury, a house, or property that's worth a lot of money, you will need to take the case to county court or superior court.
8. Get the attorney to help you file the lawsuit. Make sure it is filed within the statute of limitations. (If you don't know what the statute of limitations is, ask your lawyer to explain it to you.)
9. Don't wait too long to start the process. If you wait more than a certain length of time after the event you're suing over, it may be too late to file suit.

Tips

• Learn about the court system before you get started. You should know the different types of courts in your state or province, their names, and the jurisdictions of each court (what kinds of cases they can hear). You should also know the rankings of the courts (which ones can overrule the others). Finally, you should have a general idea of what happens to a case as it makes its way through the system.
• Unless you are going to small-claims court, do not proceed until you have found a competent, trustworthy lawyer who is willing to represent you. You are allowed to represent yourself in court, but it's usually a very bad idea. There's a well-known saying that applies here: "He who has himself for a lawyer has a fool for a client."
• There are referral services and associations which rate lawyers. In America, the state Bar Association licenses all lawyers in the state, and disciplines bad ones. Do a background check of the lawyer you pick to make sure he or she is licensed, has a good reputation, and has worked on your kind of case before.
• Make sure you understand your lawyer's payment schedule. In some cases, an attorney will work on a contingent fee. This means they don't get paid unless they win or settle the case, and they will take a portion of whatever the award or settlement is. In other cases, a lawyer will charge by the hour. Most lawyers' time is worth at least $100 per hour, more if they are very experienced. You will also usually be responsible for all expenses, such as travel time, copying documents, paying expert witnesses, etc.
• Be sure to tell your lawyer every detail you can think of about the case. Everything might be important. Remember, whatever you tell your attorney is supposed to remain confidential.
• Ask questions about the legal process if you don't understand what's going on. Even good lawyers sometimes goof up, so keep an eye on your lawyer. (But don't hover and annoy them too much! They are professionals.)
• When you go to court, dress respectably. Think like you're going to church. The judge will not be impressed if you show up looking like a prostitute or a homeless bum.
• If you can not afford the filing fee, you may file a pauperis- this is what prisoners often do. This does not relieve you of payment; it only allows you to defer it. Don't do this if there is any way it can be avoided, as the judge may view it unfavorably.

Warnings

• Any time you file a lawsuit, there is a chance you could lose. The case could be dismissed or the other side could win. This is why you shouldn't file a suit unless you really need to, because if you lose, you've wasted a lot of time and money.
• Once you've gotten started on legal proceedings, don't sign anything related to the case unless your lawyer says it's okay.
• Don't pick a lawyer based on price. A bad lawyer will cost you far more money in the long run than a good one will, even if the good one charges more. Conversely, the most expensive lawyers are not always the best ones.