If you aren't familiar with RSS feeds, they stand for really simple syndication. This basically is a quick means in which to get updates from websites or blogs. Just as your blog readers may use RSS feeds to get information on updates from your website, so too can you use your own feed to keep copies of your contents.
To view your blog's RSS feeds, you'll need to have an RSS reader - Google Reader, Yahoo, MSN, and even Outlook can be configured to receive your blog's RSS; if you use Mozilla Firefox or Google Chrome, you can download the free Feedly app, which puts your feeds into a more newspaper like setting.
A RSS reader will save the contents of any blog that you're subscribed to and will only be deleted if you unsubscribe; however, you can resubscribe as long as the the RSS feed is still live. With Feedly, you can even download podcasts (if your blog offers them)
Subscribing to an RSS Feed is as easy as clicking on the RSS icon; for Feedly, the application adds a Feedly Mini widget that shows up on all websites, so you can share or add a page's RSS to Feedly. With RSS feeds, you can download articles to your hard drive, thus saving your blog contents. If you're an Evernote user and using Feedly, you can use the Evernote sharing button in order to clip your blog to Evernote, which not only gives you online access, but desktop and phone access to your blog as well.