Book Club

SO, it's that time of year again where I try to find gifts for my nieces who I rarely see. Their birthdays are Jan 2 and 6. I got them clothing gift certificates for Christmas, but I want to do some sort of book-of-the-month club for their birthdays. ANyone have any good suggestions about this? (Or other gift ideas for a 5 and 9 yo who I like but don't know that well or see that often.)