[Plugin: WP Columns] Columns Not Working Properly

When I first installed this plugin, using the column tag did not affect my page content at all. (I want to have it in two columns)
After seeing another post on here, I added this to my theme stylesheet:

/* @group Columns */

.wpcolumn-clearfix {
clear: both;
}

.wpcolumn-wrapper-2 .wpcolumn {
width: 47.5%;
}

.wpcolumn-wrapper-3 .wpcolumn {
width: 30%;
}

.wpcolumn-wrapper-4 .wpcolumn {
width: 21.8%;
}

.wpcolumn {
float: left;
margin: 0 2% 0 0;
padding-right: 2%;
}

.wpcolumn-last {
margin-right: 0!important;
padding-right: 0!important;
margin-left: 480px;
border: none;
}

/* @end */

The second column now starts halfway across the page but is still located below the content for the left column (you have to scroll down to see it). Obviously I want them to be next to each other, not one after the other.
I am not very experienced with all this, so if anyone could help, that would be great!

http://ww.wp.xz.cn/extend/plugins/wp-columns/