It is a good idea to run a pre-migration check on the SharePoint 2007 before starting the migration process.
Open up cmd with Administrator privileges
Run the following command: stsadm –o preupgradecheck

Save the HTML file that was generated and email it to your companies SharePoint Master. (Don’t print it as it is very large)
Have the
SharePoint Master sign off on the pre-migration check and inform you if there are any site collections or content sources that are no longer needed and can be ignored for migration