CSS Float: Floating an image to the left of the text

Is this what you’re after?

• I changed your title into a h3 (header) tag, because it’s a more semantic choice than using a div.

Live Demo #1
Live Demo #2 (with header at top, not sure if you wanted that)

HTML:

<div class="post-container">                
    <div class="post-thumb"><img src="http://dummyimage.com/200x200/f0f/fff" /></div>
    <div class="post-content">
        <h3 class="post-title">Post title</h3>
        <p>post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc post desc </p>
   </div>
</div>

CSS:

.post-container {
    margin: 20px 20px 0 0;  
    border: 5px solid #333;
    overflow: auto
}
.post-thumb {
    float: left
}
.post-thumb img {
    display: block
}
.post-content {
    margin-left: 210px
}
.post-title {
    font-weight: bold;
    font-size: 200%
}