>Hi guys. I would like to know if exist any good Linux basic-intermediate tutorials on the web focus on certification exams and if there exist a good online certification exam that allow, to anyone that have study the OS and have the skill, to become a certified professional.
>
>THanks in advance.
>
>Regards.

There are three approaches:
A vendor neutral certification
http://www.comptia.org/certification/linuxplus/
http://www.lpi.org/a-sponsors.html
Beware if vendor neutral certification organizations. Some have proven less than ethical.

or a vendor specific certification
http://www.redhat.com/training/rhce/courses/
which offers 13 courses ranging from US $2,000 to US $3,000.

My choice is a certification program that is vendor neutral but supported by LOTS of Linux vendors.
Here is such a program:
http://www.lpi.org/a-sponsors.html
Mandrake, SuSE, Caldera (SCO), HP, IBM, etc..
http://www.lpi.org/c-index.html

And, one can always study on one's own and show competency by demonstration, which is a time honored method in the programmers tradition.
JLK