The part of an Exchange Server 2010 migration project that is most important is the planning stage. During this phase of the project the critical information about an Exchange environment is discovered that helps to properly plan out a successful migration.
The Exchange Server 2003 to 2010 Migration Guide includes a comprehensive planning chapter that walks you through the discovery process, including which tools and software to use, so that you learn the critical information about your environment to avoid causing problems during the upgrade.
