Wordpress TV that goes into detail about several different plugins that you can use to spice up your blog's appearance.
The video is kind of long, but it's packed with a ton of useful information and presented in a very easy to understand way. I've been watching it in little three to five minute increments and taking little side notes to help retain the information. The speaker does a good job of explaining what and why each plugin can be useful.
If you're serious about learning how to improve your site this video will be well worth the time you invest into watching it. The Wordpress platform has evolved so much from when I started out on my blogging journey a few years ago and it's gotten much more user friendly as well.