I doubt if you will find a "Linux certified place" The problem is that the Linux OS is not like Microsoft or Apple, there is no regulated board watching over it. If you really want to learn it, the first step would be to download a Distro and start using it! After all, you didn't take classes on Windows before you started using it, you?
I recommend Ubuntu. <
www.ubuntu.com> and fedora <
www.fedoraproject.org> They are both free to download and use.
There are still hundreds more out there and most of them are free. Detailed installation instructions are also found on the websites.
I have tried both, and although I prefer fedora, people say ubuntu is better. I still use vista, so i don't care much about Linux anymore.
As for places where you can learn Linux, I agree with the other guy about NIIT. I haven't been there yet, but I have heard some really good things about them.