It depends on jurisdiction, but in most of the US small claims court is at the county level, this was the way it worked the first time I sued a landlord. You go on the website of the county courthouse and get a fillable PDF for the small claims court process, which contains instructions. Generally, you fill out your information (plaintiff), their information (defendant), and then a statement of allegations or affidavit, which you sign. It's just a statement in your own words of why you're suing plus the dollar amount of damages, which can't be higher than the cap for small claims in your jurisdiction (it's usually like $5k).
After that, you send this with a check in the mail to the court clerk to file, or you can take it in person to the courthouse and hand it over with a check to the clerk. The fee varies by jurisdiction, but is pretty much always less than $100. It was $50 as I mentioned the first time I sued in small claims. After you've filed, the court will serve the defendant and set a court date, this is usually done via certified mail. Depending on jurisdiction, if they don't show you get a default judgement in your favor, or you may be required to pay for personal service, which is $25-$30 for a sheriff's deputy to go to their home or place of business and personally serve them court papers. At any rate, once it's decided you can use that judgement and place a lien against their business, including accounts, properties, etc. if they do not pay you in full within 90 days of the judgement being entered by the court. Once a judgement is entered it's part of the permanent public record, which is a big reason I recommend this. There's no way for them to get this removed unlike a website review.
That's basically the process. It may differ slightly by jurisdiction, but it's relatively easy and painless. The main issue is just that you also must personally be in court on the court date, so if you move out of state you have to be willing to travel back and you usually cannot get your travel expenses covered in a small claims case, so it may not be "worth it" financially for you. For me, it's always worth it to stick it to scumbags, even if it costs me more than it gains in dollars.