Selling art (UK) I have a couple of questions, anyone have any info?

If it's a sketch on paper then advertise it as such, but make sure it's mounted properly and you know how to post it safely. You could try selling both sketches and paintings on canvas. But if you do sketches, do them on decent-quality watercolour paper as it lasts longer. Sign your work, and date it and make sure you have it photographed or scanned. Not sure about the copyright stuff, as an individual art work is just that, but you could mark everything with a copyright C just in case. Ebay might be able to advise you.