One of the main advantages of using books is that you can find one on pretty much any subject. And while you can read the entire book if you especially want to know more about the subject, you can always use the table of contents or index (the better books for research have these) and find the chapters or pages that will give you the information you need. You can also get a good idea from the author's credentials (is he/she an expert in the subject?), the publishing company, and book reviews, as to the value of the book in your research.
Advantages of Using a Book
Disadvantages of Using a Book