Bernardo,
Welcome to the forums! Adam did a great job laying out the process to becoming an airline pilot. I wanted to add a bit to your question about the best flight school. The best school is the one that offers you the program that best suits your needs. Flight schools are not like colleges, there is no ranking system and they all prepare students for the exact same check rides that are administered by the FAA. Of course some can do a better job at this than others can. Check out this article that I wrote about finding the best flight school. I think you will find it helpful.
Chris