This was one of my favorite books when I was in high school. This is a behind-the-scenes journal-type account of that great tour. It's very funny and has a ton of interaction with Joni throughout the book. I especially remember a great moment in the book where Joni is sitting on her hotel bed singing a beautiful melody, proving to the author that she could write melodic songs (she was performing "Coyote" in the shows).
Check it out, as I said it's a great taste of life on the road in the seventies.