Now that you've created the account and signed in, you should be returned to your search results. At the top-right of the search box is a Create Alert link. Click on it to set up the alert. Your screen should look like the picture below.
Here you'll see a number of search alert options, but we recommend that you set up the search from the Advanced Settings, which you'll find at the very bottom of the list of options.
In the advanced settings, you can be very specific about the type of alert you want to set. Pay particular attention to the Frequency and Articles published timeline and Run Alert time. Then, save your alert, and you're set!