It is very common to add pictures in your posting to illustrate your ideas. It is very easy to add pictures in NEU Alumni Forum as well.
1. By Attaching files
Just click the "Write a New Post" button and you have a message box to add your message/post, then click "option" tab, there is a "File Attachment" section. Click Add/Update button to upload your files.
2. Embedding the picture inside the message.
I have enabled the "inline image attachment" feature, so that your attachment will be displayed in the message. Cool.