Andrew Barnes has created a really great post explaining USMT for MDT LTI. 

Read the full post here.

In order to automate the User State Capture and Restore task sequence steps in MDT 2010 you will need to configure your deployment share so it knows where to store the data. MDT 2010 installs the User State Migration Tool for usage prior to capture and restore tasks.

If you’re currently using Windows Easy transfer to migrate user settings and files during deployments then this post will help you to advance to the next level using the User State Migration Tool in MDT 2010.