I can help you with posting the picture!
You either have to get an account at
www.photobucket.com or go to
http://www.imageshack.us/ or go to tinypic.com I recommend you to get an account at photobucket, because you can keep all of the codes and stuff with all of the pictures they host. But if you go to image shack or tinypic, you do not have to get an account, but you cannot keep the codes unless you copy them onto a word document of something.
So once you have done that, you upload the picture you would like to post. When you do, you should see many codes (Url, Img, Tag, and something else...don't remember). Copy the IMG code, and then paste it into your post. If you would like to put it in your signature, post it into your signature. The code should look something like this without the *'s:
[IM*G]http://lalaland.com/lala/wheeeee.jpg[/*IMG]
When you post it, an image should be there!