Hi there,
I would recommend checking www.hotscripts.com for some kind of freeware that enables you to send newsletters. Most CMS's also have a feature for it.
On your HTML in email question, you need to open up <html></html> tags on a blank email (make sure you have ticked the box, "Allow HTML" if specificable. From there you can use normal HTML codes at will.
Feel free to get in touch with me, peter@ecopetition.org if you need more help.