Hello - help please...

My girlfriend's 2 year old iMac was stolen 4 weeks ago - OS was Leopard - I have time machine backups. A new iMac will arrive this week with Lion as the OS. The man in the mac shop said that a restore would copy everything back except the OS - i am not sure about this! I need to restore all applications, mail, iweb stuff, itunes library, iphoto library, documents etc but not overwrite Lion.

How do i do this please?

Thanks...

Banjaxed