Here is a link to an article with good reminders on how to read a book while in graduate school. In graduate school, more than ever, it’s important NOT to read the whole thing. The only thing I’d add (as I commented on the article) is to make sure to read the index carefully, since it contains certain buzzwords, key words, themes, and persons Noting these words creates a series of “tags” to help you remember the book’s content. Further, you can address these words/themes in your own work later!
(A bit of a DISCLAIMER, though: I found the article via a Google search, and so I can’t claim to be a regular reader of the blog itself. I just appreciate this article.)