ok im writing slowly because i know you cant read fast, hehe

to upload a picture:

look at the top of the page, above that thing that says HEY, YOU HAVE MESSAGES
theres a bunch of links, one of them called UPLOAD IMAGES

click there

a window will pop up and in it there will be several fields where you can upload image files
follow the directions on that window and you'll have no problems

you'll receive a URL adress to your file

then when you're posting a thread click the INSERT IMAGE button

this (img)URL(/img) will appear

replace the URL with the adress you've been given

hope it helps