I'm planning to study logic seriously and I think Quine's style is fine to me so i'm going to read his book.
There are two famous books by him. Namely, "Methods of logic" and "Mathematical logic".
I don't know which fits to me. This is my first time learning logic seriously. Which of those are suitable to a first-learner?
I would rather strongly recommend you to take a look at Peter Smith's Teach Yourself Logic Guide first. As the same suggests, this is a guide for students that want to learn serious logic by themselves, mostly Philosophy or Mathematics students that had just take some very elementary logic courses during their classes.