I love this theme, and I’ve used on several of my blogs. Thesis. Here are some great links to help you with customization of Thesis theme – like adding a banner in header, making some design hooks, adding thumbnails into popular posts, comments, etc.
- Customing Thesis Theme – visit the site
- 10 Ways To Customize and Enhance The WordPress Thesis Theme – visit the site
I hope those 2 resources are helpful and you too will realize this is such a powerful theme! 
