How to: HTML formatted email?

I am attempting to insert html code (centered images and formatted font text etc) into the body of an email but I am having problems doing so.

After an exhaustive internet search, I found many site that want you to PAY for a software solution, but no tutorials on how to make this happen on your own.

My stats: I am using AppleMail but also have Eudora mail on my Apple machine. Whatever mail solution works (Eudora or AppleMail) I will go with.

There must be a way to handcode an HTML email, right?

(ps, I am quite good at html, so handcoing it is no prob for me. Its getting the code to be understood by the various email software that is the trick).

I dont use Eudora, or Apples, but with Outlook, you could create a message, save it in Drafts, then drag it to an Explorer window (OK, I did read the word Apple,...), then edit it with a text editor, save it, double-click it to open in Outlook again, then Forward it. Maybe theres something similar you can do on an Apple ?