Hi,
You need a photobucket or flickr account. then once you have uploaded your pictures there, you copy the IMG code at the bottom of the picture and paste it in your post here. then click preview at the bottom of your post to see if it has worked, if it has you will see your picture, if not you will just see your code.
There are full instructions of how to upload pictures to photobucket on photobucket. There are also instructions of how to post pictures in the photo expression forum, i think it's a sticky at the top.
Good luck
Nikki
Nikki