This works in My Yahoo!. I’m not sure about other blog readers.
If you really want to subscribe to a blog, but it doesn’t have a feed/subscribe button, here’s what ya do:
Go to your My Yahoo! page.
Click on Add Content.
Click on Add RSS Feed.
Type in the name of the blog (if you were subscribing to this blog, it would be https://labibliotecaria.wordpress.com) – DON’T type in the name of the blog’s particular post that you are fond of.
At the end of the blog’s name, type in /feeds/posts/default
After a few seconds, a green line above the url that you just typed should say “You have successfully added the feed to your page.”
Click I’m Done. And you are.