I love The Magic Treehouse books! When my daughter was in Kindergarten, we started reading some of these books aloud. As she got older she read a lot of them by herself as well. They were our first chapter books. The books are not too long - ten short chapters in each adventure. The books always follow the same format - Jack and Annie go to the treehouse in the Frog Creek Woods which then spins away into another time period. There are so many things to be gained from these books - geography, history, science, music, art - I could go on and on. Check out the Wikipedia article on the books, too.
During my organization of books I realized that we have ten of these books in our library. This summer I've also discovered that my son loves the books now, too - and for my daughter it is like seeing an old friend again. As I read a book out loud she listens intently, even though she has heard it before. I love that my almost nine year old and five year old like the same books!
At the library yesterday I stumbled upon The Magic Treehouse books on CD, so I checked out the first set (which is the first 4 books). In the car today we listened to the entire first book, Dinosaurs Before Dark. Each time we had to make a stop today and stop listening the kids groaned - but how I loved those groans! It meant they were hating to stop the story. We learned about several different dinosaurs, what time period they lived in, and lots of other neat facts.
We came home and I hopped on the computer to show my children the website for The Magic Treehouse books. You can print out your own passport and after reading a book (there are more than 40) you can take a short quiz and print out a "stamp" for that area of your passport. You can also print out a picture of Jack and Annie and take your picture with them to upload to the photo gallery.
We printed our passports and took a quiz. It was fun to paste on stamp #1 in our passport. A goal was set to read (or listen to) as many Magic Treehouse books as we can during this first semester. While this isn't a part of my daughter's "curriculum", it does enrich her studies so much, and the same goes for my son. I think the audio books will be really helpful in keeping him busy when I'm doing some heavier read-alouds with my daughter. He has a CD player in his room and loves to lay on his bed and listen to books. (and as I type this, my husband has also chimed in that they are available on Amazon in e-book format - I wonder about .mp3?)
Another great feature on the site (which is also linked into the passports) are the Neighborhood Adventure Activities. These are printables with questions about places you might visit like the library, bookstore, museum, etc... You have to answer questions as you visit these places. What fun! I feel a field trip coming on.... I'm pretty sure (although I haven't checked) that there are a plethora of lesson ideas out there on the web as well.
Oh, and there is also a Reader's and Writer's Club section of the website with tips from Jack and Annie about writing, with some activities to go along with select books. You can even enter an essay contest to win your own tree house! Even if you don't choose to print the passport and set a goal of reading a certain number of books, I do think the books are just great read-alouds or as some of the first chapter books your child will read.