i haven't coded a layout in awhile, so i'm rusty on how divs all work together. the problem is that my "maintext" div overflows into my "episode-sidebar" div and also, my "header" div overflows into my "video-container" div. here's the code:

@charset "UTF-8";
/* CSS Document */

body {
background-color : #000000;
font-family : Arial, Helvetica, sans-serif;
color : #fff;
margin: 0px;
padding: 0px;
font-size: 12px;
}

A:link {text-decoration: none; color: #999;}
A:visited {text-decoration: color: #999;}
A:active {text-decoration: color: #999;}
A:hover {text-decoration: underline; color:#f9d837;}

#maincontainer{
width: 1000px; /*Width of main container*/
margin: 0 auto; /*Center container on page*/
}

#header {
height: 100%;
}

#navigation {
margin-bottom: 10px;
}

#links {
float: right;
margin-bottom: 10px;
}

#video-container {
margin-top: 10px;
}

#content-wrapper{
float: left;
width: 100%;

}

#maintext{
margin-right: 250px; /*Set right margin to RightColumnWidth*/
padding: 10px;
float: right;
}

#episode-sidebar{
float: left;
width: 250px; /*Width of right column*/
margin-left: -300px; /*Set left margin to -(RightColumnWidth) */
padding: 10px;
}

#footer{
clear: left;
width: 100%;
padding: 4px 0;
}


.innertube{
margin: 10px; /*Margins for inner DIV inside each column (to provide padding)*/
margin-top: 0;
}



/* butons*/

#modernbricksmenu2{
padding: 0;
width: 100%;
border-top: 5px solid #f9d837;
background: transparent;
voice-family: "\"}\"";
voice-family: inherit;
}

#modernbricksmenu2 ul{
margin:0;
margin-left: 40px; /*margin between first menu item and left browser edge*/
padding: 0;
list-style: none;
}

#modernbricksmenu2 li{
display: inline;
margin: 0 2px 0 0;
padding: 0;
text-transform:uppercase;
}

#modernbricksmenu2 a{
float: left;
display: block;
font: bold 11px Arial;
color: white;
text-decoration: none;
margin: 0 10px 0 0; /*Margin between each menu item*/
padding: 5px 10px;
background-color: black;
}

#modernbricksmenu2 a:hover{
background-color: #f9d837;
color: white;
}

#modernbricksmenu2 #current a{
background-color: #f9d837;
color: white;
border-color: #f9d837;
}
and the corresponding html

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
<title>Student Video Productions</title>
<LINK REL=StyleSheet HREF="styles.css" TYPE="text/css">
</head>
<body>

<div id="maincontainer">

<div id="header"><div class="innertube">

<div id="navigation"><div class="innertube">
<img src="svplogo.png" align="left" />
</div></div>

<div id="links">
<img src="uiowalogo.png" align="right" />
<br /><br />

<div id="modernbricksmenu2"><div class="innertube">
<ul>
<li style="margin-left: 1px"><a href="page.html" title="Shows">Shows</a></li>
<li><a href="page.html" title="Hire Us">Hire Us</a></li>
<li><a href="page.html" title="For Staff">For Staff</a></li>
<li><a href="page.html" title="About SVP">About SVP</a></li>
<li><a href="page.html" title="Home">Home</a></li>
</ul>

</div></div>

<br style="clear: left" />

</div>
</div>

<p>&nbsp;</p>

<div id="video-container">
<div class="innertube">

<iframe src="http://player.vimeo.com/video/12390409" width="400" height="225" frameborder="0"></iframe></div>
</div></div></div>

<div id="content-wrapper">

<div id="maintext">
<div class="innertube">

blahblahblahblahblahblahblahblahblahblahblahblahblahblahblahblahblahblahblahblahblahblahblablahblahb lahblahblahblahblahblahblahblahblahblahblahblahblahblahblahblahblahblahblahblahbla
</div>
</div></div>

<div id="episode-sidebar">
<div class="innertube">
<h2>Other Episodes:</h2>
<p><a href="episode.html"><img src="ethumb.png" border="0"/></a></p>
<p><a href="episode.html"><img src="ethumb.png" border="0"/></a></p>
<p><a href="episode.html"><img src="ethumb.png" border="0"/></a></p>
<p><a href="all.html">[view all episodes]</a></p>
</div></div>

<div id="footer">
<div class="innertube">
<table width="1000">
<tr>
<td>
<p>Bottom Navigation</p>
<p><a href="link.html">Link</a></p>
<p><a href="link.html">Link</a></p>
<p><a href="link.html">Link</a></p>
<p><a href="link.html">Link</a></p>
<p><a href="link.html">Link</a></p></td>

<td align="right">
<img src="logo_tagline.png" />
<p><img src="facebook.png" /> &nbsp; &nbsp; <img src="youtube.png" /></p>
</td>
</tr>
</table>
<p align="center"> The University of Iowa. All rights reserved. </p>
</div></div>



</body>
</html>