From what I can see, use:
display: inline;
float: left;
in both DIVs.
Also, I don't think you should be nesting one DIV inside the other; have them seperate.
<div class="left>
yadayada
</div>
<div class="right">
dodadoda
</div>
CSS:
.your_class {
left: 25%;
margin-left: -100px;
position: relative;
}
HTML:
<img src="your_image.ext" width="200" height="100" class="your_class" />
Whatever the width of your img is, margin-left should be negative half of that value.