Install the add-on, and a new Feedly icon appears just to the left of the Firefox address bar. Click it, and you get sent to your Feedly page. (You'll need to log in using a Google account.) The first time you go there, you'll find a pre-built front page, waiting for you, with news and information from around the Web. Click any story to read it. You can also mark a story as read so that it disappears from the page, save it, and share it with others via social networking sites such as Facebook and Twitter.
There are other pages in addition to the front page, including one that lists just the most recently updated news and information, another that has stories you've decided to save, another that shows the most popular stories from other Feedly users, and so on.
That's just the beginning, though. Feedly's real power comes from the way you can customize it for your own interests. Feedly delivers information via RSS feeds, and you can add information from any feed to your Feedly pages, eliminate feeds. You can also change the layout and look as well. Feedly integrates with Google's RSS reader Google Reader, so it grabs your feed information from Google Reader.
There's one slight drawback to Feedly: It can be somewhat confusing to set up and customize for the first time. Be prepared to spend a little time getting it right. Once you do, you'll find it a great way to keep up with information and news.