Just write yourself a Ruby script that downloads a webpage. Then parse the downloaded content with Ruby's equivalent of BeautifulSoup (a forgiving HTML parsing library).
That's pretty much all there is to it. You'll want to manually inspect the HTML from the page you're scraping to find patterns. For example all courses are in <li> tags, etc.
Let me know if you need more help. But I think as a first step write a program to download a web page.