On the game screen, in the lower left hand corner, you'll see a little camera icon. Click on that and it will take a picture of the part of the zoo that is on the screen. After you take your pics, go into the Zoo Tycoon folder on your computer (it's probably on your C drive, under "Program Files," and then "Microsoft Games") and look for a folder called "Screenshots." That's where you'll find your pics. You can edit them using a program such as Paint and then upload them to ZA.
Hope this helps!
Do you have a lot of space between the exhibits? I know that that sometimes makes my guests grouchy.