How to put Pictures in Posts and signiture.

I notice that a lot of people have images in their posts and in their signiture and i was wondering how to do this. I hope i don't sound completely dumb but i haven't been able to figure it out.
-Thank You

You go to the bottom of the advanced reply and click on the upload the picture button and browse for a pic. Then it tells you that the picture is in the wrong format and you politely tell the computer to go to hell and exit. I really don't know.

Yea that explains how to put it in but how do i complete the process of getting a picture from my computer on there?

On the top of the page, there is a FAQ which explains how to do the things your asking.

One thing to keep in mind, you cannot put pictures in your signature if they are on your hard drive. They have to be hosted someplace on the net. Put your pictures on a free hosting site like www.photobucket.com (http://www.photobucket.com) and use the directions in the FAQ.