Market Research

I'm looking at very much belatedly getting on this 'internet artist' bandwagon and turning some of my hobbies into something that could challenge me artistically/prfessionally and give me a little pocket change between jobs. There are two problems: self-promotion runs entirely against my grain, and I don't know the first thing about how to go about doing any of this. So I reach out to you, O internet, faithful friend and ally, to offer some sort of feedback. Please please chip in your two cents on anything you have an opinion on, I am out for data.

1. What would you, or people you know, be most interested in buying if I were to offer it in an online shop? (e.g. sketchbooks, prints of nice finished artwork, prints of existing rough artwork, original artwork, phone cases, tote bags, cupcakes, whatever)

2. Do you have any suggestions for new things I could make that there would be interest in?  (e.g. an illustrated cookbook, nicely formatted and illustrated art tips, 'art books' for things I tend to return to a lot (as if they were actual animated productions))

3. Do you have any experience with monetizing your art?  What would your advice be? Do you have any strong feelings on one online shop host over another?

Any and all feedback is appreciated (including 'stay pure! don't do this!') so please take a moment or two to tell me what you think, even if it's a general comment that doesn't address any of those three points.

THANK YOU!