First off, I think it's awesome that you have figured out "specifically" what you want to do. I'm currently scanning the industry jobs to see what's out there and unfortunately, I have not really seen any that are for just texturing, although I'm sure that they do exist. Seems like most (not all) places I've looked into want you to be able to texture and model or at minimum, model and uv map.

The tutorials on simply maya are a good place to start. There are several tutorials that cover texturing and most of the tutorials are created by people already working in the industry. Other than that, just google as there are lots of resources available nowadays.

As a texture artist, you're going to want to learn Photoshop really well. Uv mapping can be learned pretty quickly but creating great textures is another story. You'll want to be as efficient and skilled with Photoshop as you can as it's the industry standard.

You'll also probably need to learn how to use zbrush or mudbox which are sculpting programs but critical for getting great looking textures through the use of normal maps. Not sure if it falls into the category of texturing though.