MailChimp is a popular email tool, which you can use for making an email newsletter and sending out to people. It's easy, fun to use, and it's free (up to 5,000 users). I rediscovered MailChimp recently and decided to use it to make a simple email list for my NPOex project - if you go to http://npoex.com there's a link on the page for the email list, and you can see what the sign-up is like. I decided to use MailChimp partly because it was free, but also because it's "friendly" and easy to use.
More recently, I looked into MailChimp and they have a nice page that describes how marketing automation works: http://mailchimp.com/features/automation/
For example, depending on what you've heard or come across, you may have heard of systems like Marketo, or Hubspot (Hubspot also has good learning material). But it looks like MailChimp may be an especially good way for beginners to try out marketing automation - or even marketing professionals, to help get your head around some of the concepts.
For example, one of the things you can do with marketing automation is to "automate a response", so if someone takes a particular action on your Web site, you can automatically follow up. Another way to think about marketing automation is simply as "follow up".
Another way to think about it is in terms of recommendation. If you've shopped on Amazon, you might see the recommendations about "People who looked at this item also looked at" . . . and so on.
For marketing automation, if someone visits your site, and visits a certain page, or downloads a certain ebook, etc. - then you might recommend something else they might be interested, such as a particular resource, solution, or product.
So at a very simple level, you could try making an email list using a tool like MailChimp, and review their material on marketing automation. Then you might try upgrading for a period of time to a paid account, so you could try doing some automation.