Seriously (and this proves how lame things are around here) one of the most exciting things that's happened recently was finding out that homeschoolers get to join the Scholastic Book Club too. I loved the Scholastic catalogs when I was in elementary school (I don't remember them going past that at our school). So I totally geeked out when I found out we could do it too. If you homeschool, just go to their club page, sign up as a teacher (you'll need to make up a school name) and they'll have you set up within about 48 hours. (And drop me a line - I can generate a coupon to use on your first order that gives you enough bonus points for a free book or two on your 2nd order!)
Books are up to half off and they have some exclusive gift sets (Hunger games trilogy with a Mockingjay pin, for example) but do check prices before ordering, because a few books I saw were considerably cheaper on Amazon.
We should get our first order today and I know a little girl who's going to be super-excited to get some more books in one of her current fave series, Goddess Girls (by Joan Holub and Suzanne Williams). I like these books a lot too, although I think they're probably best for readers that have some background in Greek mythology already.
I'm personally very fond of book one, Athena the Brain, in which nerd-goddess girl Athena finds out she's immortal and transfers to Mount Olympus Academy, and Em says it's her favorite too (because the Trojan War and the Odyssey get covered in it):
She also really liked Aphrodite the Diva because it guests stars Goddess Girls from the Egyptian pantheon (and she's hoping they get their own series eventually-- me too!)
Scholastic definitely has the best price on them, and they seem to be releasing each book with a bonus; a set of all 8 or the first 5 comes with a charm bracelet, and at the moment the newest book (Medusa the Mean) comes with a replica of a necklace that's part of the story. Cute!