You can share libraries, including folders, resources, tags, and notes, with colleagues who also use Zotero. This is a great option for team-based research projects and coursework.
Step 1: Create a group and invite collaborators
From your Zotero library, click the brown folder icon under the main navigation and choose "New Group...". This will take you to the "New group" page on Zotero.org. (Alternatively, you can go to Zotero.org > Groups > New Group.)
You may be prompted to sign in. Make sure you use the username and password you created when you made your Zotero account. If you can't remember your username, find it in your Zotero library under Edit > Preferences > Sync.
Name your group and choose your group type (probably "Private Membership")
Click on "Member settings" and choose "Send More Invitations"
Add group members using their email addresses -- they will receive an email asking them to collaborate (make sure you give them a heads up that you're doing this!)
Step 2: Find your new group in your library
Once you've created a group, you'll want to double check that it's showed up correctly in your library.
In your Zotero desktop library, click the Refresh button (circular green arrow icon in top right corner).
You should now see your new Group folder under "Group Libraries" below your primary library in the left-hand column:
Step 3: Adding material to your shared library
There are two main ways to add items to your new group library.
All members can add items to the shared folder. Anything you add to your group library folders -- including PDFs and note files -- will be visible to anybody who is a member of that group.