Go to the Google Reader web site and if you don't have an account, and you will be asked to create one. It is free and very simple to create.
Once you have an account and you log in, click on "Your Subscriptions"
Click "Add a Feed" to add a feed you already know.
Type something you're interested in in the top search bar and click "Search for new content". It will come up with a few different feeds related to your search.
Example- a search for animals gives the following results: "People for the Ethical Treatment of Animals (PETA): The animal ... ", Friends of Animals, etc.
Know which types of feeds you can subscribe toAny of these you can subscribe to. It does not cost anything and you just add a label and click subscribe and you now get that feed whenever they update the website.
Know the unsubscription process, should you decide to unsubscribe. You can unsubscribe from a feed by clicking the down arrow on the right side of the screen. Next to the words "more options".