Here's a short "how-to":
-Click on "Gallery" at the top of the page
-To the very right of the screen is a link that says "Upload Photos" ..click that
-Choose the appropriate category that your photo should go under
-Click on browse and find the photo that you want to upload and double click on it
-Enter a title for the photo
-Enter a short description of the photo
-Enter a couple of keywords that people would use if they go to search for your photo
-Click on "Upload/Submit" and you are done!
If you choose to upload several photos at one time then you will be redirected to a screen where you can change the title, description, and keywords for each picture. Then you can hit upload again.