Your book is a record of your thoughts and enthusiasm for art. If you do not write it down or record these things in your book - then you will not receive marks for this at all.
Good books show enthusiasm and interest. It is very easy to detect when they do not.
Criteria: Your book should have a balance of the following: (these are summaries of the criteria - not the actual criteria)
Technical research - experimental examples/research using traditional and unusual materials. Your books should smell like paint, ink, crayon, glue, varnish etc. Experiments etc should be reflected upon with regard to how the effects could be used in your work - or rejected for this purpose. You should should say why and how.
Contextual research - back ground of artists and the art scene in relationship with your work, society and important social issues of specific times of interest to you and the artists you are researching. Comparisons should be made with art from different times and places. How does the information about the "times and places" impact on the work the artist makes?
Personal research - ideas and interests other than art ideas that you can maybe incorporate into your work later - (it looks good if you have researched more than you have used in your work). For example your work might be about "War" - which is not an art idea but something you can relate to your work. You would be looking for examples where artist have also.
Art research (analysis) - art explored and analysed using your own thoughts and the opinions of experts (critics, authors, artists, teachers etc). The best books have quotes and reflections on these quotes. If you are doing this correctly you will be looking at color, line, pattern, texture, composition etc in detail and discussion the use of it by the artist in the work.