WSS3.0 or MOSS2007 : UI Customization references

Heather Solomon - http://www.heathersolomon.com/blog/

How to: Customize the Display of Quick Launch -- http://msdn.microsoft.com/en-us/library/ms466994.aspx

Windows SharePoint Services Default Master Pages -- http://msdn.microsoft.com/en-us/library/ms467402.aspx

http://msdn.microsoft.com/en-us/library/ms476046.aspx