This node is currently in development. I found out that I want to do it REALLY good, so I have to do some more research. If you want to downvote it because of this, I suggest you visit it in a couple of days instead. And yes, this includes the spellchecking... ;)
Introduction
There's a very common misunderstanding among people that quoting a law accurately displays the usage of said law. This misunderstandning is more widely spread throughout Europe than the US for reasons following later in the node.
What is a law?
With a law, we are to understand the written legislation of a legitimate states law-giving institution such as a parliament. However, there are unwritten laws as well. These differ from the written laws because they are made from a multitude of different sources. Don't confuse these with verdicts, although verdicts can contribute to the unwritten laws. In some cases unwritten law can actually outweigh written law.
Where do you find laws?
The most common place is of course the country's law compilation. It usually contains the central laws and regulations given by the law giving institution of the country. However, some of the laws merely provide the framework for other regulations. A law can pass on authority to other government / state bodies. You can't expect the parliament to regulate water distribution for each county in the state or country. The logical thing to do is to outsource that to some other branch of government. The downside to this is that it creates a myriad of different regulations in a government. But this is the way it has to be.
When it comes to unwritten laws, the foundation is a bit more unclear. A source, although of very low priority, can be law literature. The literature can describe the habits of enforcing laws, and thus provide a source of unwritten laws.
How do you read a law?
Simply reading a law won't do. It's very rarely a law can be used in real life without any research or interpretation. All laws are basically subject to interpretation. E.g.: In the Norwegian constitution from 1814, ยง100 gives the people right to free speech. But if you read the paragraph you will be puzzled because it only says that free speech "should" be implemented. You have to be familiar with the language of 1814 to get the exact meaning. That in 1814 "should" meant "must".
Further on, every word in the law is subject to interpretation. What does "speech" mean? Does it include text? Does text include source code? Does "free" mean I can say untrue things about others?
This is where the court steps in. The object of the court is to interpret the meaning of the law, along with the guidelines of the law maker. In Europe, the law system relies more on the law text itself than the US which use court verdicts in a much wider degree. That's why Europeans tend to believe that the answer to the dispute is printed in the law book.
Also, the law text itself is usually very complicated. Remember, the law is there to cover a really, really, really, REALLY wide array of events. The preliminary work on a law is incredibly extensive to assure the function of a law in real life.
Referring to a law
At work I see a lot of people blurting out: "You can't do / say / mean that, because it says here so in this paragraph". And they go on to quote the paragraph. The most common mistake is that the freedom of speech gives you the right to be heard. Which is dead wrong of course. They don't consider the text of the law that says you are free to say and mean whatever you want, but it's not mandatory for a newspaper to publish it even if you send it to them. If this sounds wrong to you, think about how the reverse situation would be. So blindly referring to the law won't get you anywhere.
OK, you have looked at the law twice, and you found out that the law covers the dispute you want to argue, it's valid and you have checked that you are right. Then what?
First of all, look at the referring laws and references in the law to others. It might very well be that some other paragaph or law states that your law doesn't apply in this and that case. Usually, there's a main paragraph in the law and the following paragraphs are exceptions or additions to the main one.
Then look at what the courts thinks about the law. If you find a case that match with your dispute, you have struck gold. Referring to a verdict is always much better, since it by nature includes an example and a statement from the judge.
Then you have a very powerful argument against the other person. Be sure to include the source for credibility.