find a website to host them like
www.photobucket.com, make a new account, and upload your pictures there
they should tell you how to upload on the site
next, copy the address to the picture after you've uploaded it (something like photobucket.com/yournamehere/picturename.jpg), then come to the forum, and make a new post
along the top of the post making page there's a bunch of buttons, and one of them says 'IMG' on it
press that button, you'll notice it will make an IMG tag in your post, then paste the address of the picture into the post after the IMG tag, then press the IMG button again
this will close the IMG tag
so basically press button, paste address, press button again to close
do this as many times as you have images, but of course each image will have it's own address
add your text, and post the message as you normally would