RSS Feeds

I better understand the purpose of RSS Feeds now but still am fuzzy in building them. Can anyone help with this?

The RSS feed that we did in rapid feeds is a stand alone feed like the one that the MLIS program has. You would find that little icon on a webpage and it would allow you to subscribe to that feed. The feed would send you updates from that organization. But when I go to rapid feeds I am not exactly sure how to update my information or exactly what I am updating. When you go to add a new one, it asks you for a url. I put in my blogspot url when I created it, so when I update my blog, it should update this RSS feed. Is that correct? Should I also (which I did initially) add some of the RSS feeds that I am following? So my site has my blogsplot plus one from ALA and NPR.

Does that make sense?