Could you check Books.txt.gz at; https://snap.stanford.edu/data/web-Amazon.html which consists book ratings from Amazon. it also has product title, price, review summary etc.
Also bookcrossing dataset might be useful http://grouplens.org/datasets/book-crossing/
I guess your second question is a feature selection problem and weights will be different for each dataset.
this course at coursera gives brief information for recommendation systems and it also has a reading part. unfortunately quizzes are no longer available
course:https://www.coursera.org/course/recsys
readings: http://recsys.cs.umn.edu/readings.html
Edit: Yet another dataset for books.
Goodbooks:
http://fastml.com/goodbooks-10k-a-new-dataset-for-book-recommendations/