You asked me about images. Well, I've uploaded a few.
There is far more about images that I can easily cram, at Wikipedia:Manual of Style/Images. You need an image an Atheris matildae from a source with the right licensing.
Yours has the right licensing? You should be able to go (left side) to Toolbox --> Upload file, Wikipedia:Upload.
Remember the image must be copyright-free, or at least of a license that is OK for Wikipedia (see there image policy for specifics). If you upload an image that stomps on someone's copyright, the image will soon be removed — trust me here.