<p>I know this is probably the dumbest question ever, however I am a total beginner when it comes to CSS; how do you hyperlink an image on a webpage using an image which is sourced from CSS? I am trying to set the title image on my website linkable to the frontpage. Thanks!</p>

<p><strong>Edit:</strong> Just to make it clear, I'm sourcing my image <em>from CSS</em>, the CSS code for the header div is as follows:-</p>

<pre><code>#header
{
    width: 1000px;
    margin: 0px auto;
    padding: 0px 15px 0px 15px;
    border: none;
    background: url(images/title.png) no-repeat bottom;
    width: 1000px;
    height: 100px;
}
</code></pre>

<p>I want to know how to make this <em>div</em> hyperlinked on my webpage without having to make it an anchor rather than a div.</p>

That's really not a CSS thing. You still need your A tag to make that work. (But use CSS to make sure the image border is either removed, or designed to your required spec.)
```
```
<a href="index.html"><img src="foo" class="whatever" alt="foo alt" /></a>
```
```
EDIT: Taking original intent (updated question) into account, a new code sample is below:
```
```
<a href="index.html"><img id="header" alt="foo alt" /></a>
```
```
You're still in an HTML world for links, as described by other answers on this question.