For some reason it isn’t letting me post this as a response to your original post, so starting it as a new topic…
The design is pretty similar to a print design, but there are some additional considerations such as the width should be around 600 pixels for optimal email viewing.
The easiest thing to do is to use a program that has templates for email newsletters and customize from there. Mailchimp, for example, is easy to use and might be a good option for your first time. Check out these links for some other ideas on email newsletters: