How do i put a per page theme in a special box/div?

Well… Buidling a second sidebar is a matter of CSS & HTML… all i can say about that is that you should think of the structure you want, then create a div before or after the content (Depends on the position) and change othere containers sizes so they would all fit.

If you got something like this:

<!--======= YOUR CSS ========-->
.bodyContainer { width: 960px; }
.left { float: left; width: 300px;}
.content { float: center; width: 650px;}

<!--======= YOUR HTML ========-->
<div class="bodyContainer">
    <div class="left">
    You left sidebar
    </div>

    <div class="center">
    Your Content
    </div>

    <br style="clear: left;" />
</div>

It Should turn into something like this:

<!--======= YOUR CSS ========-->
.bodyContainer { width: 960px; }
.left { float: left; width: 200px;}
.content { float: left; width: 550px;}
.right { float: left; width: 200px;}

<!--======= YOUR HTML ========-->
<div class="bodyContainer">
    <div class="left">
    You left sidebar
    </div>

    <div class="center">
    Your Content
    </div>  

    <div class="right">
    Your Right Sidebar
    </div>

    <br style="clear: left;" />
</div>

.
I can’t build it for you cuz’ it would take me some time but that the essence of it right?

As for the Image on the side… Once you a have a sidebar to the right you can define a new Thumbnail and call it into that div class=”right”… that real easy and should be done like this:

In your functions.php file:

add_image_size('rsidebar-thumb', 600, 200, true); // 600=width / 200=height

.
Then in you right sidebar paste this:

<?php the_post_thumbnail('rsidebar-thumb'); ?>

.
And now you can enter an image for eash post with ease..