I have had a Google Alert set up for "SZSRocks", which is my user name for many web-sites, for quite a while. Thankfully, this alert has not provided any unpleasant surprises! Just to refresh my memory on how to set up alerts, I created one for the "Minnesota Mineral Club", an organization Steve and I are members of.
As for usefulness for the ERHS Media Center, students and/or teachers could use it for a specific topic search, but given the short amount of time for most research projects, I'm not sure if a Google alert would be the most efficient. Perhaps a Social Studies teacher could do an alert for a current world event and get daily updates.
P.S. I created the Google Alert! image at the top in Microsoft Word, using Word Art. In order to add this image to my blog, I needed to convert it to a jpeg. To do this, I selected the Google Alert! text box and copied it. I then opened Microsoft Paint under "Programs", then "Accessories" and then "Paint". I pasted the image into Paint. I sized the image and then did a "Save As" jpeg image. It worked really well. This opens up more image possibilities! Give it a try and let me know what you think!