I can't say enough about the importance of regular email newsletters. They boost traffic to your website, remind people that you exist, show people you are smart in your field, and of course are useful for promotions.
The success of your email marketing depends on which of those strategies you decide to use, and if you stay with it. Email marketing might sound like a thing of the past since so many social media sites seem to be better the better, more modern methods of communication. You might also be scared off by the low email open rates, email bouncing, and that horrible "but why did they do that" feeling you get when someone unsubscribes.
It's all worth it because you control the email marketing, not the social media sites; because it's a method of communication that you can rely on; because most people don't read every one of your emails; because open rates only seem low when in fact most email programs block the ability to measure open rates; because emails bounce all the time; and because those people who unsubscribe probably never bought anything from you anyway.
Building your email list is the first step in email marketing. You can collect email addresses from customers in your store, from a form on your website, or from a form on your Facebook Page. Before a person signs up you should tell them what they should expect from your email campaign. Most customers will be unimpressed if you tell them it's an informational newsletter because they don't innately understand the power of the information you could provide; but you could ethically bribe them by saying something like "Would you like receive our email newsletter? We occasionally send out special offers and sale announcements."
It will probably be easier to collect names from customers in your store than from your website or Facebook. You could collect several emails every day if you ask every customer that walks in your door. The email collection rate online is much slower, and you might find that only 1 person per week signs up.
People who sign up online are less likely to sign up if you ask them for a lot of information. An online form that asks for an email address is easy, but people are less likely to give their name, birthday, and anniversary. The birthday and anniversary information allows you to create more targeted emails during those months, and provide the customers with special offers for their special day.
The one thing you don't want to do is add people to your email list if you haven't asked them first. This means you should not buy an email list from your local Chamber of Commerce or from an email list company. Those lists of people will most likely never be your customer after you send your first "spam" email to them.
If you are looking to get started with email marketing you will first need to select an email management service. I use GoDaddy's email service; other choices include iContact, Mail Chimp, and Constant Contact. You should search Google for "email marketing" to see a list of email companies.
After you've set up your email service you will need to ask your website programmer to add the signup form to your website somewhere. Finally, you need to establish a way to collect information from people in person in your store. Try to get their name and important dates along with their email.