A couple of useful resources you should check out:

Deployment for Office SharePoint Server 2007

Office SharePoint Server 2007 Evaluation Guide

Planning and Architecture for Office SharePoint Server 2007

Planning MCMS Application Migration to SharePoint Server 2007 

Migrating from MCMS 2002 to Office SharePoint Server 2007

SharePoint Upgrade and Migration 

Upgrading to Office SharePoint Server 2007 

Migration and Upgrade Information for SharePoint Developers

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