Which album did you upload the pictures into?
One generally attaches pictures to a post within a thread (such as your ad) by using the "Paperclip" icon at the top of the post/reply composing window. It opens a new (smaller) window with directions for selecting the photos from your hard drive or picture hosting website, and attaching them in groups of 4 to the post you are in the process of composing at that time.
Frederick - The Scaleman
1978 Fiber Stream 16 named "Eggstasy" & 1971 Compact Jr. named "Boomerang"