CT,
As I read your question more closely, I realize that your question is not so much about how to set up ratings as it is about how to set up the look and feel of the posts.
You have lots of options here. Perhaps the best option would be to create a separate post for each image. This would give you lots of options for rating the Post instead of the rather limited options available in rating a PhotoSmash image. There is even a plugin YATPB (Yet another Photo Blog plugin) that is designed for setting up Photo Blogs, which might be a better fit than PhotoSmash.
There are folks using PhotoSmash for Rating type sites (see http://Foodgazing.com http://www.SavorySights.com or http://beforeafters.com ). These all use PhotoSmash Extend to create a new post on upload. http://smashly.net/photosmash-galleries/extend/
As you've probably figured out, getting ratings started is as simple as creating your Gallery, editing it in Gallery Settings, then setting the Rating Type and Rating Position (at the bottom of the first tab).
You can use Custom Layouts to display your images in any manner that you want...show the large images only, add in custom fields for descriptions or other things, show the tags, etc. Here's a tutorial on the custom layouts: http://smashly.net/photosmash-galleries/how-to/create-custom-layouts/
You can do any sort of HTML design you want in the custom layouts. It's really incredibly flexible.
If you're stuck on a specific part of this, let me know. I thought you were wondering how to get ratings started, but I don't think that was your question after all.
Cheers,
Byron