What is a Lifebook?

I have been reading everything about adoption I can. I recently went through the books the library has and picked random titles. The one I am reading now is “Lifebooks Creating a Treasure for the Adopted Child.” I have only read about half of it but it got me thinking. This would be a nice thing to make for our adopted children… including Gavin. He is at the age now where he is asking lots more questions and they get tougher and tougher. I almost always feel like I haven’t explained in a way he can understand or that I have said something I shouldn’t have. I think we all need something consistent to refer back to (especially because I am so scattered brained). The funny thing with Gav is that he knew he was adopted by Joe and he never seemed to care… then all of a sudden one day it was like he finally heard what we were saying and had a million questions. (That caught us off guard!) So maybe all this time he just didn’t understand what we were saying?! Anyway I am brainstorming ways to make this Lifebook thing work for him too. But it's already difficult. I have to deal with my feelings of guilt or insecurities in order to make this work... no one likes doing that. I want to put in child friendly facts and pictures… but when do you tell/add the not so pleasant details? Sometimes it feels like there isn’t another family in the world quite like ours or maybe I just need to get out more ;) Has anyone here made a Lifebook?