I mostly use Adobe Photoshop though for many of my older pieces I used Corel Painter 11. As for how long - it depends on the piece, but it is hard for me to gauge how much time is spent because I never really keep proper track of it. ^^; (I’m trying to keep a record now so I can figure that out.)
[Edit: Fixed wonky sentences. My brain’s running on low from a really hectic week]
Hnnnng, still need to work on this more by adding more actual interactive elements, but I like the direction it’s headed in so far!