Hi, this is you chance to see my process from sketch to vector :). I made this tutorial from 3 parts.
You will need Photoshop for sketching and Illustrator for final vector.
Learn how to find resources, how to convert your sketch to vector, how to color your line art.
Sketching in Photoshop using a graphic tablet (I use Wacom Intuos 5 M)
From sketch to vector line art in Illustrator using pen tool
How to color in Illustrator – Lineart to Color