Is the plan to make it look like the rest of the website?
Start playing with the products.tpl and product.tpl pages as they are basically what your site is built around. These can be found in customer/main in the Admin section after you click on Edit Template.
Also, go into the customer folder from the main "Edit Template" link.
This is where you can change the main look of the website.
Edit the categories.tpl page to change the way the menu system looks.
Just play with these and you will see "include" files for various pages while you are editing, so take a look at these as well.
Finally, make sure to make copies of everything so you can rollback if you mess up somewhere. What I always do is to create a file called "originalpage.tpl.save" for every file you plan to change.
Good luck!
David Young
My Wife's Jewelry Store - Many Mods...
http://www.sunkies.com/store/