Adding a picture is quite simple. First you sign up with a host service like Photobucket. You do not need their paid member features just to post pictures on a forum, the basic free service will do fine. Then you follow their directions on how to load your pictures to their location. Once the picture is located on line, you copy the img coded link from their site and just paste it in as text in your message. If you go
here and look, you will find one of my pictures the way it looks on photobucket. If I go to the line marked IMG code and copy that code, I can come back here and paste the code into the text that I am typing. Instead of everyone seeing the code, they see the picture like this.
If you right click any picture on the forum and ask it to display the "properties" you can see the path that you would need to paste into your browser to take you to that picture. It will also give you a bit of information about the picture itself, such as the number of pixels in each direction, the stored image file size and even the file format, in my case it is a JPEG file. For this picture the location it gives is http

/i290.photobucket.com/albums/ ll251/Oldman1947/Heterandria/femaleCloseup.jpg
If you copy that line of text into the bar at the top of your internet browser, remove the space that I had to include so that the whole path would display and press the go arrow, you will end up on that same picture.