Add icon or image beside your sidebar title

To make your blog interesting and attractive you can add small icons beside your sidebar title.This is most common in wordpress themes and many of the premium blogger templates .We can do this by adding CSS to individual widget title(h2). It surely will give a new look to your template and keeps your blog refreshing.

Adding icon beside sidebar title involves for steps.
[1] Finding icons /image.
[2]Uploading to any free image hosting like tinypic.
[3] Making CSS for the sidebar heading title(h2)
[4]Customizing CSS.

Before going further deep in the tutorial i am expecting that you have found a suitable image and hosted it yourself.
Coming directly to step 3.Under Edit HTML tab Expand Widget template and look for ]]></b:skin> and insert the new code above ]]></b:skin>

.widget id h2 {background:url(URL OF HOSTED PIC);
background-repeat: no-repeat;
background-position:left center;
height:25px;margin:0;
padding:10px 3px 0 30px;
line-height:1.5em;
text-transform:uppercase;
letter-spacing:.2em;
}
]]></b:skin>
</head>

Now change widget id with the unique widget id in your template.

How do i know my widget id? 

Under Layout > > Page Element section.Click On edit Button of any widget/gadget to find its ID.
A new window will open with customization option .Look for the URL of the widget .Examine the url and you will find the widget id at the end of the url.

Customizing CSS

You can customize the CSS according to your template by adding or removing properties to your css.One thing that will be most important in your customization is padding