If you’ve worked on rebranding (to any significant extent) SharePoint Portal Server 2003, you know how difficult it can be to feel confident in what you’re actually doing, due mostly to the lack of documentation on the subject.

Well, Microsoft has released two papers on the Office Developer Center to help:
Branding a SharePoint Portal Server 2003 Site:

Part 1, Understanding the Use of a Corporate Brand*****Learn what it means to "brand" a SharePoint Portal Server site, and about the different types of branding you can apply to a portal site to reflect an organization's identity.*Part 2, How to Apply Your Own Corporate Brand****Through step-by-step examples of the typical tasks involved in branding a Microsoft Office SharePoint Portal Server site, learn to change the standard banner, introduce a custom style sheet, and enhance the user experience of your portal site through interface, navigation, and page layout changes.