Are there any other node types that can have child pages added to them. I was using book, but I've lost it because I tried to add an additional "book" type and it overwrote what I had because I guess you can only have one book. I don't have much done yet so I'll most likely reinstall drupal, but before I run into this again... can another type of content have child pages?

What I'm trying to do is have a place for reviews. 1st Review is top level, and then others can either add their own review OR add a comment. I want any reviews to be actual content or nodes, but to fall under the 1st review submitted. Or I might be going after this the wrong way. I want people to be able to see all the reviews done for a single book and for each review to be connected if it's on the same book.

TIA for any help with this.
Shari