Prerequisites for migrating SharePoint 2007 site to SharePoint 2010:1. Check whether the packages (wsp features etc) in source server are same as in the target server (if not please install).
2. Check the web.config modifications made in the MOSS 2007 site (source site), if any do the same modifications on MOSS 2010 site (target site) accordingly.
The only process to migrate the site from SharePoint 2007 to SharePoint 2010 is the migrating contentDB of source site to target site.
Steps to follow for migrating ContentDB:
1. Take the backup of the source site contentDB and restore the same on target server.
2. Create the web application in SharePoint 2010, and then create the site collection (it doesn’t matter what site template you are using for creating site collection).
3. Once finished creating the SharePoint 2010 site, go to central administration --> Manage content databases --> select the web application you created for migration --> click on database --> check in the remove content database --> click ok
4.Add the restored database in the target site by using stsadm.exe in command prompt
Stsadm.exe –o addcontentdb –url “enter your url” –databasename “enter your db name”