Hmm.
I don't learn english through books very much.
I learn it through things that we encounter everyday, like video, games, music,....
I learnt a lot from them.
But well, I do have a book, written in English, which my brother gave me 2 years ago. It includes all the grammar notes in English and can help you become really good if you work with it diligently. However I've never finished it
Well back to the topic, you know, I started learning english when i was in 2nd Grade (9 years ago, I'm in 11th Grade now) o.o... It took me quite a while to get used to english, and be good at it.
Tell me more about what aspect of english you want to improve (list, read, speak, grammar, etc................) it'll be easier for me to help you.