Easy Feed Editor is a free tool to create and edit your own Feeds. Easy Feed Editor offers a wide range of features but still is very easy to use.
It does for example support RSS and ATOM and is able to directly upload your feed via FTP.
Easy Feed Editor is OpenSource and therefore completly free.
A feed works basically like a newsletter: It enables you to send information to all users that decided to subscribe to the feed. The only difference is that the subscriber's computer checks for updates of the feed rather than waiting until it receives an E-Mail. For you, that means that you do not need to set up a newsletter system because the feed is basically just a file on your webspace. On top of that, many users do not want to give their E-Mail addresses away nowadays. As opposed to newsletters, users can subscribe to a feed without giving away any personal information. This makes many users more likely to subscribe.