Her book, Galactic Derelict, was the first Sci-fi book I ever read. It was my dad's favorite, and he gave it to me to help quench my early thirst for reading. It didn't quench; it whetted.
I can't say I read a lot of Sci-fi. A good amount of Asimov, plus a smattering of other random books and authors, such as Ender's Game and War of the Worlds. But I collect Andre Norton.
The way she writes, what she writes about (usually), what she focusses on and emphasizes (or doesn't emphasize) I find likable, engaging, and comfortable. And, not only does she tell a good story, but I've learned interesting historical things from her books as well - like about the Hyksos or the post-Civil War (American) West. She writes not only sci-fi, but fantasy and historical fiction, often blending all three together. (I love how factually accurate she tries to be.)
Here are some links to various sources on her:
Her Wikipedia page
An adoring article entitled Who is Andre Norton?
Her official, fact-centered biography
Some quotes of hers on her writing
An extended interview (which has some good stuff in it, I think)
Another, more conversational interview centered mainly around one story
NY Times obituary
I might go into other observations of mine later. But for now, what do you think?