Collections
Everything added to the Zotero library appears in "My Library." You can create collections corresponding to your projects by clicking on 
above the Library pane. You can add sub-collections within collections.
If you have a collection selected when you are importing items into your library, the items will appear both in "My Library" and in the collection you have selected. These are not folders you are sorting your citations into. It is better to think of them as iTunes playlists, where the original lives in the library and the song information is added to a playlist xml file. When you remove an item from a collection, it will not be removed from "My Library" (but if you delete an item from "My Library," it will be deleted from all collections).
To copy items into collections, select them in "My Library" and drag them into the collection. The same item can simultaneously exist in multiple collections. To see which collections you have placed an item, select the item and then press the Ctrl button. The collections will be highlighted in yellow.
Organizing Your Library
In addition to storing bibliographic information, Zotero can save links to the full text, full text attachments, tags for organizing your content, snapshots of pages, notes about the items, and also stand-alone notes.
Tags
When you import items from databases, the subject descriptors attached to the items may be imported as tags. You can edit them, delete them, or add your own tags to each item. All tags are displayed in the bottom of the left column and the tags for each item are displayed in the item details column when the item is selected. Tags can be edited in both locations. To prevent tags from being imported with items, go to Edit > Preferences > General and uncheck "Automatically tag items with keywords and subject headings."
By default, the Tag Selector in the left column shows all tags present in the currently selected library or collection. As an alternative way of adding tags, you can drag one or multiple items (or files, links, and notes) from the center column and drop them onto a tag in the Tag Selector.
Notes
To create a note attached to an item, select the item from the list in the center column and either click the “New Note” button at the top of the center column (
) and select “Add Child Note”, or go to the “Notes” tab in the right-hand column and click the “Add” button.
A note will be created as an attachment to the item (it will also show up under the “Notes” tab), and a note editor will appear in the right-hand column. You can create a dedicated window for the editor by clicking the “Edit in a separate window” button at the bottom of the editor. Text in notes is saved as you type.
Zotero will sometimes automatically import information from a resource, such as a table of contents or abstract, into the notes of an item. Use the editor to change or delete these entries.
Standalone Notes - Standalone notes are not directly related to any item in your library, and will appear in the list of items in your library. To create a standalone note, click the “New Note” button and select “New Standalone Note”.
Attachments
You can set up your Zotero preferences (under General) so that when you import bibliographic information, depending on availability, Zotero will import a link to the item, a snapshot of the item, or the full text of the item. These appear as child items attached to the items listed in the middle column. As seen below, the PDFs will usually have a generic label. Right-click on the label and choose "Rename File from Parent Metadata" to change this label to the article title.
You can attach files manually by dragging a PDF (or other file) into your Zotero pane. Dropping a file into your collection will copy it into your library as a standalone item. Dropping it onto an existing item will attach it to that item.
Searching collections
Zotero searches citations, notes, and attached PDFs for your search term. Click on search (
) icon to pull up the Advanced Search Screen.
