Hi there!
You can host your pictures/sigs at several places, however, I advise: http://tinypic.com/
I use it, it's totally free, and it dosen't ask of any personal details at all. It also allows you to edit your images for free, a bit like a basic Photoshop. I love it, and I'd actually pay to use it, if there was a cost. Which there isn't.
Also, you can make sigs easily, it just depends how professional you want it. Our friend TJK makes sigs for people, he made mine - He's brilliant. I'm sure he'd happily make you one, if that's what you're looking for.
Kind Regards,
Jack