CSS beginner here, I’m at my wits end with a relatively simple css layout and was hoping someone would just look over it for me..
What i’ve got: 
CSS embedded temporarily, excuse the indenting (i’ve just come from programming and indenting was helping me make sense of it):
<!DOCTYPE HTML>
<html lang="en">
<style>
* {margin: 0; padding:0;}
body
{
font: normal 100% Helvetica, Arial, sans-serif;
background-color: LightSkyBlue;
margin: auto auto;
max-width: 90%;
}
#central_container
{
background-color: Yellow;
width: 100%;
margin: auto auto;
float: left;
}
#leftside_container
{
background-color: Ivory;
float: left;
width: 66%;
clear: left;
}
#header_container
{
background-color: DeepSkyBlue;
width: 100%;
height: 15em;
}
#header_title
{
background-color: Lime;
width: 100%;
height: 80%;
}
#header_title h1{ padding: 0; margin: 0; }
#navbar_container
{
background-color: Coral;
width: 100%;
height: 20%;
}
.navbar_links{ background-color: HotPink; }
#currentpage_content
{
background-color: grey;
width: 100%;
height: 20%;
}
#rightside_container
{
background-color: Khaki;
float: right;
width: 33%; <!--/* 320 /960 */-->
}
#register_container
{
background-color: LightPink;
width: 100%;
}
#contacts_content
{
background-color: SeaGreen;
width: 100%;
}
</style>
<head>
<title>Verge Green IT</title>
<link rel="stylesheet" href"CSS/base.css" type="text/css" />
</head>
<body>
<div id="central_container">
<!--Left-side Current-page Content-->
<div id="leftside_container">
<!--Header-->
<div id="header_container">
<div id="header_title">
<h1>#header_title</h1>
</div>
<!--Navbar-->
<div id="navbar_container">
<div class="navbar_links">
</div>
</div>
</div>
<!--Current Page Contents-->
<div id="currentpage_content">
<p> #currentpage_content</p>
<p>"Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum."</p><p>
"Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum."</p>
</div>
</div>
<!--Right-side Every-page Content-->
<div id="rightside_container">
<div id="register_container"><p> #register_container </p></div>
<div id="contacts_content"><p> #contacts_content</p></div>
</div>
</div>
</body>
</html>
What i’m aiming for: 
(Vague text alternative: Where the register_container fills the rightside_container up to the height of the bottom of the navbar_container. And the contact_content fills up the rest of the rightside_container as the current_page content does on the leftside_container. )
I think i’m having some trouble because of the floating i’m trying to do.. and i have no idea why there’s empty yellow space on the left of register_container/contacts_content. Nor why i can specify height for things like the header_title but not the register_container.
Really appreciate any help!
I think you have some minor problems with values you have given in the Width and height field.
This works fine for me.