Ok to attach a picture you use the icon at the top of your reply box that looks like a tree.
Ok here is how you upload them-
At the top of your reply box is a icon that looks like a tree. It is two to the right of the smiley.
Click on the icon. It will bring up a box.
Click on browse. Another box will appear.
Click on browse again in that box.
Navigate to the place in your computer where the picture is. Select it, and then in the second box click on upload.
The second box will disapear.
In the first box click on insert.
This will upload your picture, and you should see it displayed in your reply box.
Repeat the process to upload another picture.
If this wont work for you then you can upload them to http://tinypic.com
Once the pictures are uploaded they will give you a set of links. copy the one that says for forums. I think its the second link from the top.