coding problem need help

I need to know how to change the content size of my template layout with out loosing my sidebar. I have tried to fix it myself and loose the sidebar every time. I am new at coding the layout never tried to change one before. If you look at this page https://cooltoysforkids.info/my-cool-toy-store/ you will see my problem. I need the page wider because it is not showing all the plug-in that I have installed.

not sure if this help but this is the content are code, what do i need to change.

/* CONTENT AREA */
.contentArea {
	width: 100%;
	background-color: #f0eff0;
	background-image: url(images/content_bkgd_tile.jpg);
	background-repeat: repeat-x;

}

.contentArea .container {
	padding-top: 30px;
	padding-bottom: 30px;
	background-image: url(images/content_bkgd.jpg);
	background-repeat: no-repeat;
}

.contentleft {
	width: 650px;
	padding-left: 40px;
	padding-right: 40px;
	float: left;
	border-right-style: solid;
	border-right-width: 1px;
}

.contentright {
	padding-top: 20px;
	float: left;
	padding-left: 30px;
	width: 210px;
}

.imageright {

	margin-left: 5px;
	float: right;

}

#search {
	margin: 0 0 1.4em 0;
}

#searchbutton {
	margin-left:7px;
}