Why can't my students access my course?

From BbWiki

Student access to Blackboard sites depends on the 'course availability' setting in your Blackboard control panel. By default, new Blackboard courses are 'unavailable', meaning instructors see them but students don't. When you're ready for students to see your site, you need to make it available. You can also open some areas to guests. Here's how:

COURSE AVAILABILITY: To make your course accessible to enrolled students, make it available:

    CONTROL PANEL > SETTINGS > COURSE AVAILABILITY = YES

GUEST ACCESS: To make your course accessible to guests, first turn on guest access:

    CONTROL PANEL > SETTINGS > ALLOW GUEST ACCESS = YES

In addition, you need to make sure your items in your navigation menu are guest accessible.

    CONTROL PANEL > MANAGE COURSE MENU

Select "Modify" next to the area you want to allow access to and then select "Allow Guest Access".

Note: Some areas, such as the discussion board, cannot be made accessible to guests.