Premium Upgrade

I have WordPress 3.5.1 (now 3.9) installed on my laptop. I’m trying to build a new WordPress blog/site for a customer who requires a certain layout structure to post books. I’m unclear as to what PREMIUM does for me to build a new blog. Can you point me in the right direction? Did I waste $99????I’m confused.

Background: Last year I purchased the PREMIUM WordPress.com Upgrade for $99.00 and WordPress.com last Fall for my “test site (http://vbcdesigns.wordpress.com) but never launched it. Did I even take advantage of Premium along with the TwentyEleven theme?

HELP????