This new beta version that I am trying has a very simple layout. I got it from Misha's hub. Here is the URL:
It works by either entering your URL for your blog or the topic of your blog. You put the information into the designated area and select the search button.
Many results will be returned. First, make sure the results are relevant. Next, I shift my focus to the Global monthly Searches section. The more higher the number under this category means that people use this keyword more.
You can also further modify your search by selecting different categories on the left side of the page or you can use the advanced options hyper link located right below the search button.
I hope this helps, and if you need more information then just ask.