Actually, it's pretty easy.
Log into Photobucket, then go the the album where the pictures are that you want to post. Once you get there, hover your curser over the picture you want to post. When you do that, you'll see a drop-down menue that has several different links. The one you want is at the bottom of that menu, and it the "IMG code". Place your curser over that link and LEFT click. It will then say "copied". Come back to the Forum, and paste that link into your post. You will ONLY see the link code, not the picture at this time. Hit enter a couple of times to put a line space below your link, and do it for your next photo. Once you have all of the pics you want, post as you normally would, and you pictures will be in the post so you can see them.
Hope this helps.