Migration from SharePoint 2007 to SharePoint 2010 and URL Redirection

HI All,

In our current Organization we are using SharePoint 2007 Collaboration sites for all the departments.  The Content DB size is nearly 1 TB and one site collection.

we are migrating this SP 2007 site to SP 2010.We are splitting 1 TB content DB into one web application and multiple site collection(one site collection for each department, nearly we have 20 departments) in 2010 using third party migration tool.

my question is after completing our 2010 migration, how can we redirect if users access their bookmarked 2007 site/document url into 2010 multiple site collections.

provide any examples or reference url's will be appreciate.

Thanks,

MSS