Working for a consulting agency, I often have to develop a migration plan along with an approximate timeline of how it will go.  Below is my list of things to do or verify when performing an Exchange migration, along with commands or links to posts on how to do it.

Install Exchange 2007 – 2 hours

Configure/Verify OWA – 1/2 hour

Move OWA certificate – 1/2 hour

Configure Public Folder replication – 1 hour

Move Offline Address Book – 1/2 hour

Configure/Verify internal and external autodiscover – 1 hour

Create Storage Groups and Databases – 1/2 hour

Move-DatabasePath  ServerStorageGroupMailboxStore -EDBFilePath X:PathToDatabase

Move-StorageGroupPath -identity SERVERName of the StorageGroup -LogFolderPath X:PathToLogFiles -SystemFolderPath X:SystemFolderPath

Mobile phone reconfiguration – 15 minutes/phone

Move mailboxes – 8GB/hour on a Gigabit LAN