Note: My Library contains all uploaded items, collections are just organizing those items. This means that items can be located in multiple locations at the same time.
1. Select the item you wish to add a tag to
2. Locate the Tags tab
3. Click Add
1. In the bottom left hand corner, you can search for and select the tags you are looking for
2. When you select a tag, it will turn blue, and you can then select more to narrow your search
1. Create a Zotero account online here.
2. In Zotero > Edit > Preferences > Sync > Enter Username & Password