There are 2 ways of doing that.
First one is to indeed upload your picture to the site.
You can do that by clicking the text Additional Options
at the left below the edit box.
Now you'll see a box where you can fill in a loctaion where your photo (or whatever file) is.
You can also click the "Browse" button next to it.
After clicking "Browse" a box will open where you can browse your pc for the picture/file.
Now you can finish your text, and after posting it (will take a bit more time as the file will be uploaded).
Your picture will be added below your post as a thumbnail.
Forum members who click on that thumbnail will see teh full size picture.
You can also upload your picture to an image hosting site.
But all i've seen of those require you to register.
Once uploaded, you can link to those pictures.
The hosting site will probably help you by offering the corect link plus codetags.
If not, you can find the location of your pictures, and put them in [img]http://tags.
This would look like this: [img]http:/www.somepic.org/hgkogehrkekgiah423.jpg[/img].
You don't need to put the codetags in yourself.
You can just click the
button above the text edit box (i just did that to paste the link to that same button picture.
The cursor will be at the correct position to type or paste your link to the picture.
CrossRoads beat me to it, but i think i had all possibilities covered.
Hmm, i see some unexpected behavior in the forum software, nevermind that.