I don't want borders around all my images, only some of them, so I specify a photo class in my CSS. Here is my code:
CODE
.photo {
margin:8px;
border:1px solid;
}
Then I do my photo's image tags like this:
CODE
<img src="/images/blah.jpg" alt="Blah pic" width="32" height="52" class="photo" />
The alt and width/height tags are there for xhtml compliance, and then specifying the class has it use the CSS to style it, giving it an 8 pixel margin, and a 1 pixel solid border. You can of course specify colors and various thicknesses and style for the border, I just use a very simple one. That should work fine for you, assuming your stylesheet is working properly in general.
Peace,
sam