Blackboard

I think Blackboard is a good tool for sharing files in a closed network. I've used Blackboard both as a student and an administrator. 

As a student, I find it extremely valuable for class powerpoints or articles that are posted - cause I can't loose them! It has some features where you can give tests and quizzes, but otherwise, I don't find it to be very interactive. I'm sure there are better platforms out there for this kind of thing.

I manage an administrative Blackboard site for the Communicative Sciences department. I find it a useful for giving students access to forms they frequently request as well as listing resources available to them in the department. By having sections like "Graduation Information" and "Advisement and Registration," I can direct them to the information on the site rather than answering the same questions over and over. I can also link them to other sites with information on certification, etc.

The main benefit to Blackboard is that it is an online resource that can only be accessed by a defined list of users, so all you information does not need to be made available to the public. However, as a teacher, I'd probably look into other platforms such as cloud computing that may provide more tools and flexibility for communicating with students.