Here's a step-by-step example of how to upload images to the wiki.
STEP 1 - Type image link on page
While editing a wiki page, you add an image link by typing [[Image:MyImage.jpg]] where you want to place an image.
Call the image anything you like — the name you use does not have to match the name on your machine. Just make sure to use the same extension (.jpg, .gif, .png) on the wiki image link.
Once you are done with your page edit, click the Save page button.
STEP 2 - Click the red image link
Once you save the edits to your page, you will see a red link in the spot where you added the image link.
Click the red image link to replace it with the image you want to upload.
STEP 3 - Click the browse button
The wiki will take you to a special upload file page that allows you to do the upload. Click on the browse button to select the image you want to upload.
STEP 4 - Select image to upload
Clicking browse brings up a file selection window that lets you pick the image on your computer that you want to upload.
Notice the image name on your computer does not need to match the name of the image in the wiki. Only the file extensions (.jpg, .gif, .png) need to be the same. You can name the wiki copy of the image anything you want.
STEP 5 - Click upload file
Once you select the image you want to upload from your computer, you can type some description into the box to describe your image.
Click the upload file button to do the upload.
Once the image is successfully uploaded, you will see a window with the image showing that the upload was successful.
STEP 6 - Your wiki page now has the image!
Now if you browse to your wiki page, you will find the image link replaced with your actual image.
That's all there is to it!