Header for html newsletter mail

I’m planning to write a page where one part is setting up some kind of newsletter.
I’m thinking about having three different templates for the look and then fields where I insert the headline in one field, one field for the text area and then on fields for an url link and one where I upload a photo that will be added to the newsletter. All these fields are inserted into a MySQL table.

I guess I can build this as a simple html page and just leave room for where the different parts will be placed that are stored in my db.

But, I think the html page that are supposed to be sent have to have a different look than a regular web page, right?
Is it just the headers that are different or what else should I think about when I’m building this?

Any ideas, warnings or hints?

I found a solution/guide to my question now.
http://www.adobe.com/devnet/dreamweaver/articles/html_emails.html

Yeah, looks as if you have discovered the basic problem. HTML email !== webpages.

Try some of the links this search turns up, they will often be accompanied by rules and guidelines to help pick your way through this minefield: [google]beautiful html email templates[/google]