Graphic Design pointers?

If I was to buy photoshop, create graphics, clipart like images, logos, anything graphic that was sellable. Put a watermark on them then sell them. How would I go about doing that. Obviously I would need to create the graphics with something like photoshop then host somewhere to sell them like my own website but can someone point me in the right direction as to get some information on the topic, specifically how to sell graphics online. I am unsure as to how to actually sell them onwards and who to. Any general information regarding the topic would be most helpful, thanks