A common question is "what is the most important thing for someone representing themselves in court to know?"
There are actually a couple of answers to that. In reality it is knowing what you don't know. In other words, don't read a few articles online or go onto one of those awful "represent yourself" websites and then suddenly start believing that you are a match for an attorney in a case. You can certainly learn enough to be a contender, but you won't if you try the tricks and crap that some of the nutjob websites tell you to try.
The way a lawsuit is won or lost is through knowing the various rules and using them.
The first and most important aspect of representing yourself in a lawsuit, also known as appearing pro se or pro per, is learning the Rules of Civil Procedure.
One of the first classes a law student takes is "Civ Pro". The reason for that is that the Rules of Civil Procedure set out how a case happens. If you have a lawyer with a good knowledge of the rules opposing a lawyer that doesn't understand them then the knowledgeable lawyer will win 90% of the time, even if he isn't as good as the other one.
All states have Rules of Civil Procedure although they may also be called Rules of Trial, Rules of Court, or some other name.
To a person choosing, or being forced, to represent themselves every hour you spend spend studying these rules will be returned ten fold in value.
As we discuss in The Guerrilla Guide to Legal Research: Finding the Law for Non-Lawyers, a litigant should read through the rules carefully and then run case law searches to find out how the court has defined and applied the rules.
We are working on a Guerrilla Guide to Civil Procedure, but it is still a ways from being completed, mainly because the subject is so complex. In addition, it is an area of the law that is "legal-ese" heavy and it is incredibly hard to take the complex subject and not only inform pro se parties about it but also do it in a way that is easily understood. Since we are dedicated to not just producing books that cover a topic but also to writing them in a way that they can be understood by anyone, we are still some months off from having this book completed.
In the meantime, if you are representing yourself then take the time to find and read the rules and also research how the courts are applying the rules. You'll be glad you did, and the other side will be sorry.