In a notebook go to create a new page:
Add a back ground by inserting a picture:
Position and size the picture as you would like. I suggest using something with white to the bottom and right so that it doesn’t look chopped off as you add notes to the page.
Once you have the background positioned as you would like, right click on the image and chose “Set picture as background”. (Image has to be selected as shown above, or the option wont come up.)
Once you have the rest of your template created, you will save:
In OneNote 2007 you go up to the format drop down and choose Templates.
In newer versions you can go to the View section at the top and choose from a variety of additional options. Once you want to save you can go into most field, for example paper size, and the option to save template will be listed at the bottom the same as it is in the 2007 version. The work area will pop up on the right hand side toward the bottom of the field you will see:
Choose to save the current page as a template.
Now under templates, it shows up under “My Templates”