I dont know how deep you want to get into doing a custom template, but here's some info that may help (and may not
)
if you used tables, you would have better control of the layout and could put auctiva image tags inside the table cells, splite the page into columns like you're asking, etc.
html tags typically have a starting tag and an closing tag. for example, for bold text you use <b>text to write in bold</b>
the <b> is the opening tag for bold format, the </b> is the closing tag.
now, on to formatting of layout of page. probably easiest would be to use a table. then you could put auctiva image tags in the cells and if the size of the cell is predefined (by pixels or percentage of space available) then should go pretty smoothly.
think of a table like the cells in excel. the rows across are indicated with a <tr> tag and end with a </tr> tag
the columns in each row are denoted by a <td> tag (stands for table data) and end with a </td> tag.
so for a basic table, that has 2 columns, and two rows
XX
XX
the coding would be
<table>
<tr><td>stuff for top left area</td><td>stuff for top right</td></tr>
<tr><td>stuff for bottom left</td><td>stuff for bottom right</td></tr>
</table>
You can, of course, make tables much more complex with cells spanning more than one row, tables within tables, etc.
But wanted to give you the general idea of the html coding for a table.
For your needs, you could probably use a WYSIWYG html editor and then edit the code for putting in the auctiva image tags, and any other auctiva tags you want to use. there are some free ones out there. I use dreamweaver myself (which is pricey) and flip back and forth between the WYSIWYG editor and the code editor.
here's one of the various free html editors that are out there and that lets you switch back and forth between WYSIWYG mode and code mode.
http://nvu.com/index.php and dont forget, when you drag an image into a WYSIWYG html editor, it will put the url for the image as a path on your hard drive. you have to put the web url for the image in yourself.