There are a number of good job sites available in which you can search for jobs using RSS feeds. Some have unique content and others pull job listings from many sources. The best one varies by your industry and location.
CareerBuilder.com - Displays job title and 2 line description, Click button “Get jobs via RSS”.
CollegeRecruiter.com - Displays job title, location and 2 line description, Need to use separate query builder. Then look for text that says “Your Custom Link is Below”
Craigslist.com - Full feed with entire job listing., Result page has RSS auto discovery. You can also scroll to the bottom and look for RSS button.
Hotjobs.com - Displays job title, location and 1 line description, On the results page, look for XML button on left side towards the bottom
Monster.com - Displays job title, location and 2 line description, On the results page, scroll down and to the left there is a XML graphic and text link “Save as RSS feed”