Angus & Robertson have some great discounts on books for babies, under 5s, under 9s, 9 to 12 year olds, teens and young adults:

Babies and Toddlers | Angus & Robertson
For 3 - 5 | Angus & Robertson
For 6 - 8 | Angus & Robertson
For 9 - 12 | Angus & Robertson
Gifts for Teens and Young Adults | Angus & Robertson
For Young Adults | Angus & Robertson