For my internship in Fall 2015 I maintain a subscriber list of over 1,000 and create and send weekly messages containing relevant information for our specific subscribers. The service that we used is MailChimp, which I had only heard of. It presented a great opportunity for me to get to learn the ins and outs of a new technology!
Check out my handy guide on how to use MailChimp here!
A basic search on YouTube gave me a couple videos I think could be useful for those who are visual learners. I will note that the videos seem to show a slightly older version of MailChimp. My guide was created in Fall of 2015 and reflects the MailChimp you will encounter if you sign up today.