Where do I train?

This is very specific to the field you want to get into. Also where you live in the world is going to determine whether or not there are courses available.

We suggest that once you've identified the specific area you want to train in, speak to local career guidance people and hunt out what is local on the internet, the library, publications etc. Try and talk to people that have done the course before you enrol. These courses are expensive and you want to make sure your money is well spent.
Make sure you get the course to work for you! Try and get portfolio quality shots of your work as you progress so that you finish with a lot to show for your efforts.

Also remember there is an alternative. You can buy some materials and training manuals and give it a go yourself!