Hello SRB,
You may have to first upload your image to an 'image hosting' site like
imageshack which could involve a very short registration process.
Once you have that done, upload your image to that host, then copy the 'link' information of the image to the post you wish to make or as part of your profile.
If you continue to have any difficulties in figuring this out just reply in this thread and we will do what we can to assist.