[fiveohpatrol]

All you have to do is hit the Browse button in the Attach file: part of the page that loads when you are typing your post.

Or you can upload a picture to your members site (if you have it setup) and then put the url like this with [ ] instead of { } and your username and file name ofcourse...
{IMG}http://members.mustangworks.com/five...ol/picture.jpg{/IMG}