Best way to setup RSS feed for a custom WP blog plugin

Created a new completely custom plugin and created a new type called BlogType, and I can create blog posts inside the admin panel. Now, the question is how to set up RSS feed. I would like to not use a paid service, so I was thinking I would have to setup a cronjob and then allow users to enter their emails and every midnight I would have to post last day's RSS.

?xml version=1.0 encoding=UTF-8 ?
rss version=2.0
channel
 titleRSS Title/title
 descriptionThis is an example of an RSS feed/description
 linkhttp://www.example.com/main.html/link
 pubDateSun, 06 Sep 2009 16:20:00 +0000/pubDate

 item
  titleExample entry/title
  descriptionHere is some text containing an interesting description./description
  linkhttp://www.example.com/blog/post/1/link
  pubDateSun, 06 Sep 2009 16:20:00 +0000/pubDate
 /item

/channel
/rss

They would all get an email like this with in their email from the post's data. Now, I am not sure if a RSS feed is just a feed of XML formatted data you receive every day or every time you post something. Does this make any sense? I am not too familiar with RSS, because I never used it, but I think I understand the gist of it. And is there a better way?