You first have to upload your photos to a web based photo hosting site like www.printroom.com
. There are other free services like hunting-pictures.com, ehomebook.com, yahoo.com, and others but you'll have to do some investigating on those.
Once the pic has been uploaded, open that pic at the website and right click on the photo, then click on properties, then highlight the url address shown and copy it (put the pointer in the highlighted area, right click & select copy).
You will now need to paste that url in your next post (or temporarily in an open file if you write your posts offline) and then use the board code - www.ar15.com/forums/help/code.htm
to make it a link or an auto loading image.
If you need more help let us know.