If you observe the post titles in my blog, each post title starts with one image looks like below,

To add images like this for each of the posts in your blog all you need to do is to just follow the below steps.

• Create a light wait image of your favourite choice.
• Make sure that the logo/image format and name end with .icoEx File name : mylogo.ico
• Now upload it to a photo or file hosting site ex : Yahoo Geocities http://www.geocities.com/krishnaspage/mylogo.ico
• Once your icon is accessible outside go to Dashboard in your blog
• Dashboard->Layout->Edit HTML> Check the expand Widget Templates
• Back up the existint template
• Now start editing HTML code
• Fine the below line

<a expr:href='data:post.url'><data:post.title/></a>

• change the above line to look like below
  

<a expr:href='data:post.url'>
<img src='URL of your image' style='border: 0; margin: 0; padding: 0;'/> &#160;
<data:post.title/></a>

once you changed this save the template and preview it. Now you should be able to see the images besdie your post titles.