TimeZero wrote:Thanks to all your advices! I finally ordered not 1, but 3 books. I think i'll be able to get solid bases with those books and then i will be able to enjoy "Invincible" a lot more.
Here are the 3 books I ordered:
1- "Go for Beginners" by Kaoru Iwamoto
2- "Lessons in the Fundamentals of Go" by Toshiro Kageyama
3- "Learn to Play Go: A Master's Guide to the Ultimate Game (Vol.I)" by Janice Kim and Soo-hyun Jeong
I hope I made some good choices here!

Number 1 on your list is an excellent beginner's book. I personally don't consider number 2 an appropriate book for anyone who isn't close to SDK level, and even then I didn't get much out of this book, although many people swear by it. Number 3 may be too easy for you if you already have a solid understanding of the rules.
Invincible is, in my opinion, a dan-level book although some people seem to have gotten something from it in the SDK range. But the game commentaries in Invincible are quite advanced, and I have put this book aside for when I am quite a bit stronger.
When I was a beginner, the three books that had the greatest effect on my level were Graded Go Problems for Beginners Vols. 1 and 2 and Opening Theory Made Easy. The latter two books especially have great value because you can profit from re-reading them a number of times.