well, first off an iframe is not really suggested, but for beginners i guess its alright.. i use to use it.. but now i moved to some little php...
anyways i am downloading the psd now and i will try to slice it for you, no promesses.
Well after looking at your slice i think its not that bad.
if you want an iframe at the image number 13 you need to add a style to your td
look up for the <td> <img src..... and remove the <img src="....> line and inside td add :
CODE
<td width="your width" height="your height" style="background: url(images/yourimage13);">
<iframe src="home.html" name="main_iframe" width=" your width (same as the td)" height="your height (same as the td)></iframe>
</td>
so youll have your iframe and your image on the background, huhhhh i donno if by default the iframe is set as transparent... if not than i think you need to add the following to it :
CODE
color="transparent"
inside your iframe code.
but again, i would of remove your image and add a bgcolor to it and not have an iframe but a full html page.
Good Luck