Step 1: Create a query in the Clearinghouse
Go to http://mercury.ornl.gov/clearinghouse

Enter a query in the Simple Search box and click "Search"
(alternatively, you may want to select "Advanced Search" and enter in a more complicated query)

You will see the results of your query (see Step 2).

Step 2: Create an RSS Feed
(RSS="Really Simple Search")

Click on "RSS Feed" in the top right corner.

You will see a webpage that says CSAS Clearinghouse Search Results RSS Feed.
Select a browser from the "Subscribe to this Feed Using" bar.
Then click on "Subscribe to this feed".

Depending on your browser selection, follow the prompts to name and subscribe to your RSS Feed.