Uploading an image is easy. Justo go to FembotWiki, look for a link that says "Upload file" and click it. Then click on the "Browse..." button, choose a file from your computer, check the "Ignore any warnings" box, and click the "Upload file" button.
You have to be logged into FembotWiki of course.
Adding your images to your gallery is more complicated, but if you want to find out how, you can check out Wikipedia's help pages. Most of the basic stuff there applies to FembotWiki.