It is good to read just about anything you can get your hands on.
It doesn't matter what your style of writing is, or will be, nor does it matter what genre you have an interest in, it is vital that you peruse just about anything and everything.
Newspapers and magazines, children's books, fiction, non-fiction, science-fiction, mystery, how-to and technical, and even the dictionary and a thesaurus.
The greater your own vocabulary, the better your work will sound.
Yes, I said sound. Think about it a moment. When you read work, most people tend to subvocalize... that is, they say the words in their heads. If you tend to start a lot of sentences with 'the' or use the same descriptive word over and over, your work starts to sound very bland.
There is one other thing that I recommend. I feel that it is very important that a writer be familiar with at least one foreign language, if not familiar with several. There are two reasons for this. One is that it broadens your vocabulary and increases your knowlege of other cultures. The second reason is that when you learn a foreign language, it helps improve your understanding of your native language. In this way, your own writing will improve.
So, whether you want to write the next best-seller, or just some steamy trashy novel, reading is valuable.
And one very important other reason why you should read if you plan on writing is that you may suddenly feel inspired by what somebody else has written. Maybe it's just a snippet in their work that you can expand upon. Or perhaps you will find a style that you want to emulate. There may be a character who is similar to one of yours. The possibilities are greater than the number of books ever written. Maybe you're not even interested in writing a book! It doesn't matter.
While reading, it is important to do one thing. Study the work. How has one particular author laid down the plot to keep you interested? How do the characters interact? How does the author convey information to you? Does he/she only let you, the reader, know what the main character knows? Or do you know something that the protagonist needs to find out?
Read read read says I.
Yes, it is just as important to write. After all, that's what you're trying to do, right? Write write write! It is just as well to become prolific at writing as you do at reading; but the basics to becoming a good writer are to be a good reader.
That's what this post is about... reading.
One must also be a good listener. After all, you can gain many ideas by listening to what other people say. But that is not the topic of this post. But, for the sake of argument, apply the same rules of reading to your listening skills.
And read some more!