I would recommend you practice and online articles. Why? Books are full of theory and you get so bored that you want to kill yourself. It's like a subject in school you hated. No matter how hard you try you get distracted. At least I feel this way. Go on pokerstrategy.com. There are articles with examples and explanation to everyone of your questions. They have a golden rule: Do what we tell you and you will win. After I have read their articles I got better and started getting some cash out of freerolls
and cash tables. I tried to read a book and I was disappointed. The author said "I won't tell you what to do, it depends on the situation" In other words he said that he would right more than 500 pages where you won't learn how to act but you would be able to choose. This sounds pretty stupid to me.