Here are the steps to posting an image you found somewhere else on the net
1. Right-click on the image and click Properties.
2. Next to where it says "Address/URL" select the text beginning http:// all the way up to the end (it might be long and you might have to move the mouse down whilst selecting to get it all).
3. Then, release the left button and hover over the selected text - then either right-click and Copy OR press CTRL and C (to copy).
4. Come back to your post and paste what you just copied. Now select this http:// ... .gif or http://... . jpg and then click on this button
This will insert the necessary tags around your image.
5. Click preview to see where it has been placed.
Generally when wanting to perform any action it's best to select the text or image code on which you wish to apply formatting (e.g. center) and then click on the button as this then automatically puts the tags before and after.
I hope this helps - and if not please say which step things go wrong and I'll do my best to assist
AS ANOTHER TIP - RATHER THAN MAKING LOTS OF POSTS IN THE CONTEST THREAD BEFORE YOU GET IT RIGHT, TRY IT OUT IN THE "PLAY AREA" - AS THESE ARE AUTOMATICALLY DELETED AFTER A DAY OR TWO