These are the steps for migrating SharePoint to a new server:
Backup the site using the STSADM utility:
stsadm –o backup –url http://<server name>:<port> -filename <pathfile.bak> -includeusersecurity -nofilecompression
Create a new Web Application for restoring the site:
Go to Central Administration -> Application Management -> under SharePoint Web Application Management -> click Create or Extend Web Application. Fill in the necessary fields, click Ok and wait until the process completes.
Restore the site to the new Web Application:
stsadm –o restore –url http://<server>:<port> -filename <pathfile.bak> -includeusersecurity