You need to have a syndication module on your website. If you are using a CMS like joomla or wordpress, those have rss inbuilt. If your site is custom you need your content to be syndicated in xml. If this does not mean much to you will need to hire a programmer to prepare your content for rss distribution
You can use Java, if you can program in that language to use xml and make a feed. The easiest way, if you do not know how to code is to use a program that does it for you, such as Joomla or some other CMS. This is if you want a feed from just the internet to a website. You can also create rss feeds for mobiles.