Hey MW,
You can upload a pic directly to the site or using a 3rd party hosting service like PB, flickr etc.
To use the forum directly to add a pic to your post, just open a new post window. Below the text window, you will see (in blue) the words, "
+ Attachments and other options"
Click on the + sign and a drop down menu will open. You can then attach and browse yur pic files, allowing you to select pics from your laptop, pc or wherever you have the pic.
When done, just hit "post" as u normally would.
Screen grab here: Hope that helps.