[Theme: Twenty Twelve} Category page content and styling

I’m struggling to get both the content and look I want on category pages. I am new to WordPress as of January and I’m unclear about the best way to proceed. This screen shots of what I want and the modifications I’ve made already to a new category-9.php file in my Twenty Twelve child theme.

http://www.aridgardening.com/march-15-test/

I am not what changes I need to make and where I need to make them.
The options seem to be:

#1 – Work with: get_template_part ( ‘content’, get_post_format() ) … and modify references to this somewhere.

#2 – Put formatting information into content-_____.php … as mentioned in the Twenty Twelve theme category.php comments. I am not sure how to approach this or how to reference it.

#3 – Add divs with formatting inside one of the .php files … but I’m not clear on which one.