There are many free photo editing programs available for download on the net, I like the simplicity of Picasa by Google. You don't have to purchase expensive software to get great photos.
Start by getting up close and personal. Although it's great to have at least one photo showing your subject in it's entirety, if you're selling online, your potential buyer will want to see details!
Here is my original photo of one simple bead.
And here is my original photo after I cropped it
And here is my final, sharpened copped photo, with added shadows and fill light. Not significantly different from the second photo, but enough to make it "just right".
Play around with it and have fun, you'll see how easy it is to have professional looking photos in no time!