How can students upload images (to put in Discussion forum)?

Greetings,

I'm brand new to Blackboard, having done my own web course management until I wanted my students to be able to maintain a Field Journal on-line and didn't want to have to learn how to set up and run blogging software. The journal type in the discussion forums seems to fit the bill, except that for the life of me I can't figure out how students are able to include images in their posts. The insert image tool (when HTML is enabled) has two choices, a URL link (not desirable) and a link to an image file that they've somehow gotten into the Blackboard system. That's the part that's stumping me. There are several help sections that sound appropriate, but I haven't found one that actually describes how to upload a file so that, in this case, students can then insert an image into their blog post.

I'm hoping this is just a newbie problem; Blackboard seems to have its own language, which I'm not learning fast enough!

Thanks in advance for any insights,

Cheers,

John