Moreover, the position of each line has it's own significance, so we can see that 
the seemingly cryptic glyphs of the hexagrams are actually densely packed with information for those who can read them. Lets take apart a hexagram now so that you can see what it's made of: 

Hexagram 11, Tai (Peace) 
Upper Trigram, K'un, the receptive, earth. 
Lower Trigram, Ch'ien, the creative, heaven 

Here we see the hexagram's component trigrams. 

K'un is the trigram of unmixed yin, feminine, receptive qualities. We shouldn't get too wrapped up in the terms masculine and feminine here, because what is being referred to is tendencies of nature rather than male or female human characteristics. It is associated with adaptiveness, darkness, nourishment, and yielding. 

Ch'ien is the trigram of unmixed yang, light, strength, creativity, oneness. It is the sky to K'un's earth, the day to K'un's night. Since the light lines tend to rise and the dark ones tend to fall, and since K'un is on top and Ch'ien is on bottom, the total image is of heaven and earth coming together in peace and fruitfulness. 

However, the hexagram can yield to yet more analysis in terms of it's nuclear trigrams: 
 

Putting these two together gives us hexagram 54, The Marrying Maiden, 
 
which is yet another relationship between yang and yin, in this case a relationship of dependence. In ancient China, a man would marry his main wife in an arranged marriage in which love did not necessarily play a part, and then he might take a second wife for love. This second wife, however, was in a fairly unfortunate situation of being very much subordinate to the main wife and being kind of a fifth wheel in the family. The means of finding peace in this situation is to act with humility. Thus, the nuclear hexagram gives us an added layer of information to work with. 

But we are not yet finished exhausting the available information in the hexagram. Each line has it's own significance: 
 

This may seem to be a baffling density of information, but don't worry. Just concerning yourself with the overt meaning as described with each hexagram is enough for now. 

Each I Ching reading produces sometimes one, but usually two hexagrams. These represent the current condition, the most desirable course of action, and the outcome. The way that the course of action and the outcome hexagram are known is by the changing lines. 

Lets do a sample divination and I will show you how it works. 
 
In the "3 coins" method, we toss 3 coins for each line of the hexagram. 
Heads Tails 

Each possible configuration of the three coins signifies either a changing yin line, a changing yang line, an unchanging yin line, or an unchanging yang line: 
= unchanging yang =  
= unchanging yin   =  
=   changing yang  = 
=   changing yin     = 
The actual configuration of the coins doesn't matter as long as you are consistent in whatever configuration you are using. Lets say that you have tossed the coins and have come up with this configuration: 
6.  
5.  
4.  
3.  
2. (red dots denote changing lines) 
1.  
This is hexagram 46, Pushing Upward. When you have changing lines in your hexagram, you reverse the value of the lines to get the hexagram that denotes the outcome of the situation, which in this case is: 
6.  
5.  
4.  
3.  
2.  
1.  
hexagram 62, The Preponderance of the Small. 

But wait, we haven't got there yet! For each hexagram, there is text that goes along with the changing lines, and which give more specific advice in respect to your question. You only read the changing line texts for those particular changing lines which you drew. This changing line information is important and can change the whole meaning of the hexagram in relation to your question. 

I hope that this has gotten you interested in exploring the possibilities of the I Ching. I can promise that if you come to know the wisdom of this ancient book, you will never be the same.