Board Thread:Support Requests - Designing Your Wiki/@comment-10350197-20130804102929/@comment-4902411-20130813140011

Use the special page for uploading images in your wiki to upload a file. Take a note on the file types given at the bottom, only those are allowed. After you've successfully uploaded an image, return to the article where you want to place it and in the source mode, use  to place your image. Remember that the sizes can be altered by adding a  at the end of the file name.

Example :

More information to be found here.