Giles studied accounting and real estate after leaving Blaxland High School, working in property management before moving into public housing management for the Aboriginal and Torres Strait Islander Commission (ATSIC).
Giles mempelajari akunting dan real estate setelah meninggalkan sekolah tinggi, bekerja di manajemen properti sebelum berpindah ke manajemen perumahan publik untuk Aboriginal and Torres Strait Islander Commission (ATSIC).