How to chance descriptions for WordPress blog?

Where can I change the description of the website…the meta description that would show for my homepage on a google search?

You can change that in WordPress dashboard – Settings – General – Tagline.

Sorry, I think you misunderstood me. I don’t want to change the tagline. I want to change the description. Here is an example.

The tagline is the “Web Analytics and & Reporting”
The description is the “Google Analytics lets you measure your advertising ROI as well as track your Flash, video, and social networking sites and applications.”

I want to change the description

In WordPress tagline = description.
If you want to use different description from tagline you can use one of several WordPress SEO plugins. My favorite one that I use for most of my websites is this: