Chad Hovell

Select extra layouts from the post editor Screen Options menu. 
There are now 24 variations to choose from!

Three Column Screen Layout

Three, four and five column screen layouts for the post editor.

TristanChambers

Columnizer is a jQuery based WordPress plugin that formats your content into columns. All you need to do is embrace your content in a single set of shortcodes denoting the number of columns you’d like. Like this:
<pre><code>[threecolumns]
Lorem ipsum...vitae nunc.
Curabitur fringilla...consectetur arcu.
Proin id...pretium eros.
etc...
[/threecolumns]
</code></pre>
The rest is taken care of for you. Just write out the number of columns (up to twelve) followed by the word ‘columns’ with no space (as above) and your column formatting needs will be satisfied most splendidly. Other column plugins need you to divvy up the content between sets of tags. Columnizer does it for you!
To customize the margins between columns edit columnizer.css. Alternatively you could override the rules in your own css file by adding an extra level of hierarchy. Something like this:
<pre><code>#main #columnizer .first div {
 margin-right: 8px; /*changed spacing to 8px*/
 margin-left: 0 !important;
}
#main #columnizer .last div {
 margin-left: 8px; /*changed spacing to 8px*/
 margin-right: 0 !important;
}
#main #columnizer .column div {
 margin-left: 8px; /*changed spacing to 8px*/
 margin-right: 8px; /*changed spacing to 8px*/
 border-left: 1px solid grey; /*new rule to add slick dividers*/
 border-right: 1px solid grey; /*new rule to add slick dividers*/
}
</code></pre>
WP Columnizer is based on the jQuery plugin “Columnizer” by Adam Wulf.

Columnizer

Wordpress Plugin to columnize content automatically

Three Column Screen Layout vs Columnizer