A quick way to find really short and concise videos on any feature of your D2L Brightspace course can be found here.
If you are interested in a specific feature, you can quickly search (e.g. discussions, dropbox, calendar, assessment, quizzes, chat, classlist, etc.).
Also, when you log in to your D2L, in the right upper corner you will have a box named “Instructor Help” which has the link as well.