It is important to use persistent links given in the databases, because the URL in your browser will often eventually time out and will no longer be useful to your students.
For copyright purposes, it is important to use the links within the databases to direct your students to the articles instead of saving the PDF and including the PDF in your Blackboard course. Many publishers do no include uploads in their licenses, and the databases track usage and downloads of articles in order to compensate publishers.
Having your student log into the databases also has another benefit of encouraging your students to learn how to use the resources provided by the library for future research.
Unfortunately, there is not consistency as to what these links are called across EbscoHost, ProQuest, etc. In some they are called "permalinks" or "Copy Link", regardless of the name they are the same thing, a persistent link. Make sure to find that link on the page and copy and paste that link into Blackboard.