Blackboard courses are set to “Unavailable” by default; the instructor must make them “Available” in order for students to see and access the course from the Blackboard homepage. To set course availability using the control panel, navigate to Customization→Properties and set the course availability to “Yes.”
Here is a short visual tutorial of the required steps: http://edtech.mst.edu/support/blackboard9-1/courseavailable/