Here is a gradebook that I published.
Check it out. See what you can change.
if you want people to collaboratively edit that spreadsheet, you have to invite them by email address (on the SHARE tab). The alternative is to invite someone with the "Invitations may be used by anyone" option echekd and post the URL in that invitation email for others to use... then as people click that URL, they will be given access - and you, as the owner, may remove people or even turn off the ability by unchecking that same option whenever you want to stop allowing others to access that way....
Please share your ideas on this topic.