There a couple of ways.
You can upload your photos to your own location/web page like photobucket.com
You can then insert a link or image into your post using the buttons in the quick reply box.
Or you select the GO Advanced button below the Quick Reply text box.
Here you can scroll down and choose Manage Attachments.
The File Uploader will appear and you can select Add Files.
Next a box will appear labeled Upload Files From Your Computer.
Now press the Select Files button.
There is also a place at the bottom of the forum where you can test this.
I hope this helps?
Dave