If you have blog then you can easily do RSS submission. If you want to do RSS submission submission for site then you need to create RSS file with the help of RSS generator tool. After this upload it on your site. Now search some RSS sites and submit your url, title, desc..
Simply submit your RSS feed to rss search engines and directories there is a large list at: http://www.rss-specifications.com/rss-submission.htm
RSS feed is the xml based content format which is used to distribute news, contents, updates, etc. Generally people, who has blogs and they regularly update it, create RSS feed for their blog and ask people to subscribe. By doing so people who frequently read blogs, get to know about the update of the blogs. You can also create RSS feed for your website.