Here's the code for the first floor floorplan. You can rework the others as needed. You will need to make some default image that will appear when nothing has been clicked on yet.
You will need to adjust the size of the rocker and relaxing photos to match the size of the room photos, or you will get some weird resizing issues.
<!-- ----------begining of code------------- -->
<table width="100%" border="0" cellpadding="5">
<tr>
<td>
<map name="FPMap1">
<area href="" onClick="document.mainimage.src='images/parlor08.JPG'; return false;" shape="rect" coords="201, 165, 298, 276">
<area href="" onClick="document.mainimage.src='images/rockers.JPG'; return false;" shape="rect" coords="198, 13, 301, 115">
<area href="" onClick="document.mainimage.src='images/relaxing.jpg'; return false;" shape="rect" coords="86, 296, 195, 335">
<area href="" onClick="document.mainimage.src='images/frontrm.JPG'; return false;" shape="rect" coords="87, 18, 183, 110">
</map>
<img border="0" src="images/firstfloor.jpg" width="336" height="365" align="left" usemap="#FPMap1">
</td>
<td><img src="someDefaultImage.jpg" width="380" height="280" name="mainimage"></td>
</tr>
</table>
<!-- -------------end of code-------------------------- -->.