Recently at my day job we have been trying to hire a Jr. Graphic Designer. We had one applicant that looked promising and it was my job to get an understanding of his technical knowledge, with a focus on InDesign as we use that program for all of our layouts of any document more than a single page. He seemed to have a general understanding of how master pages work. So then I asked him what he thought of InDesign styles. He then acted as though I didn’t know what I was talking about and asked if I meant fonts. I said no, I meant InDesign styles. It was clear that he didn’t know what InDesign styles were, nor how to fully utilize them.
I discussed this with a friend and fellow graphic designer. I see styles as the lazy way to work in InDesign (I really hate having to do anything time consuming and tedious), but she had a much better term. They are efficient. They make design and further tweaks and changes easy and time efficient. I have to agree that she is right on this. Even though to me it lets me be lazy, it also makes me have much more time to create other design jobs.
So here is the Tutorial on how and why you should always use InDesign styles when working on any document more than a page long.
To begin open up a new InDesign Document. Go ahead and use the default settings: Letter size paper, Portrait layout, .5 equal margins on all sides, Facing pages. Now you will need some text. First use the text tool 
to draw a text box that fits in all of the margins. I just copied and pasted several previous blog posts texts to the document. Any text will work as long as you have various paragraphs and such. Don’t worry if the text is longer than your current text box (we can fix that later). If your text is not longer than your current text box, just hit control+v or option+v a bunch of times within the text box (this will make it much longer than the current text box).
Now open up the various style windows. 
I like to put them all into their own pallet. Everything you paste in will have the default paragraph style. Go into the paragraph style select basic paragraph, right click on it and choose edit style. 
A dialog box opens up with various parameters to choose from, you can get more parameters from the tabs on the left. Turn on the preview button in the lower right hand corner and start changing the parameters. You will then see the text change as you change the paragraph style. I changed my basic paragraph style to have Helvetica Neue 10 pt font with normal leading, left justified alignment with no hyphenation.
Now there are several ways to create new paragraph styles (these steps can be the same for creating any type of new style.) First I’ll create a new Paragraph style for the headers. I’ll select the first header and change the font to the way I want it with the character window. 
With that text still selected I will hit the drop down menu in the Paragraph style window and choose New Paragraph Style. The Style already has all of the the attributes of the selected text. I just need to give it a name and hit o.k. I can now choose the headers character style for the text I have selected. Now I can go and select the text for any header and in the paragraph style window just change it to headers and the text will format to my header settings.
Now I need a new style for the dates. I want this to have all the same attributes as my paragraph with the exception of being italicized and have grey font. I will unselect any text and hit the drop down menu and choose create new paragraph style.
In the general menu page I named the style dates and based it on basic paragraph, 
in the basic character formats I changed the font style to italic, and under character color I changed the tint to 40%. I then select the text that I want to be in the dates and in the paragraph style window I choose dates.
Now lets make that text span across several pages. On the bottom right of the current text box you can see a little red box with a plus sign in it 
(the plus sign indicates there is more text that past the boundaries of the current text box). Add 2 pages to the current layout by going Layout->Pages->insert page or through the page pallet drop down menu. With the direct selection tool (the one that looks like a black arrow) click on the little red box with a plus sign in it. You will see that the icon changes from an arrow to a tiny text box.
Go to the next page and with the mouse click and drag to create a text box that automatically fills with the text from the last page. Now if you are like me you have another text box with a little red box with a plus sign in it on the second page. Click on it again. Once again your icon has changed to a little mini text box. See how the icon changes when you hold down the shift key. Hold the shift key and then click on the upper right hand corner of the margins on the next page. All of the rest of the type has now autofilled as many pages as needed in order to show all the type. (If this didn’t work for you make sure you had enough text to fill up several pages before trying this.) This also works to auto fill text into text boxes on document pages that are linked in master pages.
So now you should have a document several pages long with paragraphs with their own style, headers with another style, dates with another style, ect. Here is where the real strength of styles comes into play. Say your creative art director comes to you and says, The Client hates Helvetica font, I need you to go in and change everything to Times New Roman. Go to your style window select the basic paragraph style then hit the drop down menu and choose style options (edit style if your right click the selected style) and from there go into basic character formats and change the font to Times New Roman. 
Turn on the preview and see what happens. All of your paragraphs with that style have changed! Now the dates have a little orange box around them as they have inherited the Times New Roman, but it doesn’t know what to do with the italicization from the last font. 
From the paragraph style window choose the dates style and edit it like the last to fix it. Wow this tutorial is getting long. I should end it here for today, but I will definitely come back and expand on this further. I’m sure you can see there are more than just paragraph styles, there are character styles, object styles, table styles, and cell styles. All of these allow you to change and update entire documents in a matter of seconds. Heck don’t wait for my next tutorial, start playing around and I’m sure you will see why you should always use styles, then you will have more time to be lazy and surf the web like me.