So, just to take one example, here is a page in Canvas which contains the RSS feed from my Growth Mindset Cats blog: Canvas RSS-Inoreader.
Here's how to set something like this up:
1. Get an Inoreader account. Everything you need to do is part of the free Inoreader service! Go to Inoreader.com.
2. Find the RSS feed you want to use. You can get the RSS feed for a blog, or you can grab the feed for a specific label at that blog. Any kind of RSS feed will work.
3. Subscribe to the feed in Inoreader. Just copy-and-paste the feed address into the upper right-hand corner. Make sure you add the feed to a folder; you can put multiple feeds in the same folder if you want to combine different sources.
4. Export the folder as RSS/HTML. Click on the folder, then click on Folder Settings at the top of the Inoreader screen, then Folder Information, and then click Export to turn it on. After you turn on the export, you will see the different Export options:
5. Configure the HTML Clip. Now that you have turned on the folder for export, click on the HTML Clip link and make your choices. For the Canvas page I made, I put in a title and set the items to 5, with "magazine" as the view option.
6. Configure the iframe in Canvas. Copy the iframe code from Inoreader, and then adjust the width and height as needed. I set the width="750" and height="1400" but you can choose what best suits your needs (although you need at least 750 pixels width for the magazine view). Paste the HTML code into your Canvas page and you are good to go!
After you set up the RSS feed(s) like this, the content will update in Canvas automatically!