You can determine the <div's position using absolute positioning like so...
<style>
div#bob{
position: absolute;
top:100px;
left100px
}
</style>
<div ID="bob">content</div>
OR
<div style="position:absolute;top:100px;left:100px">content<div>
Either giving the same result; a layer 100 pixels from both top and left. The first would enable you to define the co-ordinates through an external *.css file or through styling in the headers.