Hi Terrill,
From the FAQ:
How can I style my list to look like [insert your desired look here]?
Since this plugin does not include any predefined designs, it’s up to you to style your most popular posts list as you like (you might need to hire someone for this if you don’t know HTML/CSS, though). However, I’ve gathered a few examples that should get you started.
In your specific case, however, the default HTML output may not be fit to do what you’re trying to do. You’ll need to modify it:
How can I use my own HTML markup with your plugin?
If you’re using the widget, simply activate the Use custom HTML markup option and set your desired configuration and Content Tags (see wp-admin > Settings > WordPress Popular Posts > Parameters for more); or if you’re using the template tag / shortcode, use the wpp_start, wpp_end and post_html parameters (see wp-admin > Settings > WordPress Popular Posts > Parameters for more).
A more advanced way to customize the HTML markup is via WordPress filters by hooking into wpp_custom_html or wpp_post. For details, please check the Filters page on the Wiki.
Additionally, for the hover effect (I guess you want to show/hide the text when the cursor moves in/out the image) you either use Javascript or CSS3 transitions.
I could probably help you with the first part (adjust the HTML), but you didn’t provide further info or a live example.
