I didn´t knew anything about photoshop when I started.
My inspiration came from those speedpainting videos on you tube.
If you ever do the leap, I recommend you start with simple cell shading.
Once you feel confident, you may try other tricks.
You can´t imagine the amount of study and research it took me. I learned a LOT from the tuts here in DA, you tube, and I recommend live stream so you get that "I can do that" feel.
Now that I am working digital, I only go back to traditional media to sketch some ideas on pencil and paper.
"Once you have painted with light, there is no turning back"