What resources are available for Sharepoint Designer 2007?
Chapter 27 in the MS Office SharePoint Server 2007 Administrators Companion is titled "Using Microsoft Office SharePoint Designer 2007 with WSS 3.0".
The Wrox Programmer to Programmer book titled Beginning SharePoint 2007 has a few pages in Chapter 5 / how to build workflow solutions with SharePoint Designer 2007, and a "Try it out" exercise for creating a Page Layout using SharePoint Designer in Chapter 13.
I hope this helps.
Frank