The best way to interact with the Blackboard is to have your class inherit from BlackboardFollower, which will automatically subscribe and unsubscribe it to event and note notifications. All you have to do is override the methods so you can choose how to handle the notifications as they come in.
The Gametime module has a Timeboard object which has it's own Blackboard. It is used to send information out, and also keep track of time without requiring objects to access the Gametime data directly. Check it out to see how it talks with its blackboard object.