Hi there,
I'm not quite sure if you're talking about pictures in your profile or in your posts, but you can do both.
To add a profile picture:
1. Click
Profile on the bar in the top of the page.
2. Under
Modify Profile section, click
Forum Profile Information.
3. You should find it there; just type in the link to the picture's url.
To add picture in your post:
1. Upload picture with
http://imageshack.us/2. Copy the script that you are given into your post.