Looking for beginner's tutorial on creating website headers

[NaturalGirl]

Hi everyone, I'm very glad to have found the forum. I'll try to be a little specific because I know very vague questions are hard to answer. I'm creating a new website, and while I know HTML and how to do all the basic stuff I have no idea about graphics and how to create a nice header for the site, and buttons that aren't completely boring and lacking creativity. So, several people pointed me to Paint.net and I've downloaded it, but don't know where to start to learn how to make my header. Where do I find some detailed tutorials on how to make unique text styles and different graphic effects? I'm looking to make something fresh-looking like the headers in the following examples:

http://www.radiantonraw.com/

http://www.therawfoodcoach.com/ How does she do that green wavy stripe, for instance?

I'm really green when it comes to graphics, so any help would be appreciated. Thanks for your time.

Debra