1. How to read?
Reading with great interest, simply is enough to improve your writing ability, vocabulary and knowledge. Anything you read has a piece of Knowledge in it. It is up to you and depends on how determined you are to know and understand each word you read. Some people skim through a book rather that giving it a through read. But I suggest, reading a small paragraph daily by knowing and understanding the meaning of each word is more than enough to develop your language skills.
2. What to read?
Everyone has their own varied interest. Books are available in a large number of genres and apart from that there are a number of poetry,journal, etc. You must decide what you need to read. Think on what interests you the more? Romance, Drama, Classic, Sci-fi, or what ever and start with a simple book on that genere.
3. Fiction vs Non-Fiction
Fiction is simply a story of ones imagination. Starting from the story line to the setting and characters, everything flows out of the authors imagination. When you read a fiction you are simply reading through some ones imagination. That does not mean that the wild imagination does not hold any knowledge. A fiction too requires a lot number of reality in it, in order to be digestible.Eg of a fiction is : The Alchemist br Paulo Coelho ( and it ia a very good to start with.)