You can visit the official Microsoft Migrating from Windows XP to Windows 7 site here: http://tinyurl.com/yz2uogt
There are some nice videos tutorials and steps to take when migrating from Windows XP to Windows 7. And yes it is true you cannot directly upgrade from Windows XP to Windows 7 you can take some steps to ensure a smooth process.
Thanks again and good luck!
Microsoft Windows Client Support