Here is a good link to get you started Martino.
I am not in a trade but I have 2 friends that are Electricians so I can offer second hand info. One has his Masters License so he can do jobs on his own. He also works for a large corporation and makes a pile of money and is never out of work.
My other friend works for a large company and does not have his Masters License. He made $96k last year but he worked tons of overtime. He also has to go where the work is so he is currently staying in a motel all week and driving 9 hours each way to come home on weekends. He has been an Industrial Electrician for about 10 years.