The I Ching is a book of divination, but that does not mean it is only a "fortune-telling" book. Especially nowadays it is more a book of advice and wisdom.
Divination originally was a means to find out what the gods or ancestors or spirits or whatever had in mind. In modern words we would call it: finding out what your intuition says. I like the old way better, calling it gods, but many people have no idea anymore what gods and spirits are. They are only looking for them somewhere outside themselves. But I think they are both: in- and outside.
If you ask God for guidance, you do it by praying. An excellent way, but in many situations not practical. For everyday life there are possibilities closer to everyday life. It is difficult to pray 5 minutes before a meeting, and get an answer. Or while driving on a highway. The strange thing about the I Ching is, that it is a book of wisdom, which actually answers you right away.
Why do people throw coins, or see a paranormal medium, or read tea leaves, or go to an astrologer? Because, to hear your intuition, you have to stop rational thinking. There is nothing wrong with thinking, but it overrules the faint voice of intuition or whatever spirit guides you. By throwing coins you take the first step on an irrational path, and you leave the rational one.
The danger when consulting a medium or astrologer and all those other people offering their services: there is always a part of this person in the answer. Some try only to get your money out of your pocket, but most have not such low ends. They genuinely want to help, but they are helping you according to their own view on things. To find someone who only makes you find your own solution is an impossible search, because they are extremely rare. This is the reason why the Yiying has survived so many centuries: she gives YOUR answer and nothing else.
Phrase your question. The way of putting it is very important. Do not ask for a solution, ask: what does fate have in store if I do this - and a second question on the same issue: what if I not do this (or if I do that). I Ching does not tell you what to do; it will help you to tell yourself.
Very important: when it says "good fortune" then this is not a predicton, it means "if you do what the line says, THEN you get good fortune". So do not act blindly to a good or bad word.
Get 3 coins. What kind of coins is not important. Too big ones are difficult to tumble around in your hands, but shaking them in a box works fine too. Decide which side of them is rational, active, male, bright: yang. And which side is emotional, female, mysterious: yin. Usually the head is used for yang and the tails for yin.
Throw them once: this is the bottom line of a hexagram. Draw the line as indicated below (the complete hexagrams given here are only an example: yours will look different):
When you have thrown the coins 6 times you have a complete hexagram. Always start at the bottom, every next line above the previous one!
Now it looks for example like the left hexagram above. On the homepage 'choose' you find hexagram 53. When you change the 'old' lines into their opposites, it will look like the right hexagram above. On the homepage 'choose' you find hexagram 49.
First you read the text of hexagram 53. In this case the hexagram talks about accomplishment by continually staying faithful to it. Lines 1, 4 and 6 are 'old' or moving, their text is important. They give you clues about what you can do best in this situation. Line 1 is about action, 4 about decisions and 6 about spiritual achievement and influences. Here, an emphasis on these three realms means that hexagram 53 changes to hexagram 49: revolution, sudden and total change and renewal.
For many examples of readings and for learning: following the questions and answers on Clarity's website.