The site you mentioned http://thepatternedplate.wordpress.com/ is customized and there is not really a step by step guide to show you how to update your blog to look like exactly like someone else's who has used the Custom Design upgrade to customize the look of their site.
What we can do, however, is help you learn what CSS you need to add to make specific changes. For example, here are two past posts that make similar requests:
To make the built in header image in Imbalance 2 full width, see http://en.forums.wordpress.com/topic/enlarging-your-header-image-in-imbalance2?replies=4#post-790098
To make the top navigation menu in the Imbalance 2 theme horizontal instead of vertical: http://en.forums.wordpress.com/topic/align-menu-tabs-side-by-side-in-imbalance?replies=22#post-764995
For other issues, please post a new thread in the CSS forum for each one.