So, here's a question my sister (who is learning chess now) asked me that I never really bothered to think about, mostly because the answer seems so basic.

Q: How do you study chess books? (I.E. Opening books, Silman/Seirawan books, etc).

 Hmm... Can you explain what you mean?

I think the answer is basically, it depends on the book. A book like MCO-14 is basically a reference book - I just use it to look up how I could have improved on my opening play, once the game is finished. For a puzzle book, I give myself a few minutes to solve the puzzle and then once I think I've solved it (or have given up trying) I look up the answer and move on to the next problem. For something like a Silman/Seirawan book, I'd just read it once through (slowly and carefully though, trying to absorb as much as possible from it). If they give an example with a long series of moves and very few diagrams, I'd set up the position on a chessboard and play it out along with the text.

For opening books I would just read them once through and then play a bunch of games where I try to put the ideas into practice; look up the openings afterward and see what I can do better next time.

For an endgame book I set up the position on a chessboard and play it out along with the text (including all variations given by the book) and try to understand each and every example. 

I've bought a gambit opening book a short while ago. The only way I can actually read it is by setting it up and reconstructing the game. On each move I try to think of what I would do and I see how every opening turns out. Then I figure which opening suits me best (which position it tends to lead to).

With each ! ? !? or ?! I take extra time to read the move. I've read only 3 games today, but it opened up new perspectives to the game and it helped me developing my own play style more accurately. 

putting things to practice is of course the next step. Right now I'm getting familiar with the english opening. Sticking to it mostly to finetune

It is really subjective because each person will learn differently. My personal experience with books has been to fish ideas. Other people I have know just absorb move lists. I learn a lot from books that push me to think for myself, but also have the needed guidance to help you along. What I find most important is to question how the stronger players think, how their own analysis differs from my own. I will not sit back and accept authors telling me, 'now white is better'. Nope, you need to tell me why, I want to see some proof. Always be on the lookout for ideas in chessbooks that will teach you how to create in chess, not simply ape actions.