One of the features of SharePoint Document Libraries is the ability to check a document out. doing so provides you with exclusive write access to the document. Other can still view the document while it is checked out to you but can’t edit it.
You can check the document back in to update the version for everyone. It is also possible for an administrator to override a users check in if required.
All of this this plus more is covered in the video I created. Let me know what other sort of tutorial videos you’d like to see.