When add references to Mendeley, keep in mind that importing references into your Mendeley account may not bring any available full text file with it.  You may have to download the full text separately and then attach the file to the reference. 

It's also a good idea to synchronize your Mendeley account after adding references.

1. As you search in the database, and select or mark the references you want to export.  Databases usually offer a way to mark the references you want, and save them to a marked list or folder.  If you can't find this easily, check the HELP section of the database found in the upper right corner of the database window.
2. From that marked list or folder, select the option to Export.  If you have the option select exporting in RIS Format.  Once you have done this, select the save or export button to export the references.
3. Depending on which browser you use, you should get a file downloaded to your computer. Do not open the file. 
4. Use the +Add File button in Mendeley to browse to the downloaded file, and add the file to Mendeley.  You should see the references added to your Mendeley collection.

The Web Importer is an extension for your web browser that lets you import references from sources that do not have a clear way to export references.  You can download the Web Importer from the Tools menu in your Mendeley Reference Manager.  Once you download the Web Importer, you should see a little Mendeley icon in your browser's extensions.  If you use Google Scholar frequently, you may wish to bookmark the Web Importer.  Here's how it works:

1. Be sure to have your Mendeley web account open in a browser tab; Mendeley uses the web account to pass the information to your Mendeley Reference Manager.
2. Once you do a search in Google Scholar and have a result list to work with,  select the Web Importer bookmark to initiate the Importer.  
3. You will see a window open with a duplicating the result list in your Google Scholar search.  The duplicate list will allow you to select the results you want to move to Mendeley.  You may also have the option to save any available full text.
4. Select the results you wan to move to Mendeley and then select save.  In your Mendeley Reference Manager select Sync, and your references should be in your account.

Your Mendeley account includes access to the Mendeley Search.  Mendeley Search is a crowdsourced library of references identified in millions of Mendeley accounts.  All Mendeley Search results are anonymized and no user data is shared.

1. Access Mendeley Search by selecting Search for Article Online from the Reference Manager Tools menu, or selecting the Search heading in the upper right of your Mendeley Web account.
2. Mendeley Search will perform a keyword search across the crowdsourced library, finding relevant sources referenced in other Mendeley accounts.

Sometimes you may need to create a reference from scratch.  To do this, you should create a reference manually.

1. Select the +Add New button in the upper left of the screen.
2. In the menu, select Add an Entry Manually.
3. A blank reference form will open.  Select the type of reference you need (article, book, etc.) and fill in the form to create the reference.

Some citations may have an identifying code in the citation.  Examples of these codes include a digital object identifier or DOI, a PMID or PubMed ID, or an ArchiveX ID.  You can use these codes to import a reference into Mendeley.

1. Select the +Add New button in the upper left of the screen.
2. In the menu, select Add an Entry Manually.
3. In the Add Entry Manually form, type the code into the Identifier field at the top of the form, and select the Add Entry button at the bottom of the form.
4. Mendeley will search for the code you typed in, and if it finds a corresponding reference it will populate the reference with what information it finds.  Depending on the information Mendeley finds, you may have to add information to complete the reference. 

Use the +Add New button to add a file or a folder of files to Mendeley.  Select +Add New, select File(s) from computer and then browse to the file you with to import to Mendeley.

You can add papers or articles to Mendeley by dragging and dropping a PDF into the Mendeley Reference Manager window. Mendeley will automatically extract the metadata from the file to create a reference for that file. 

Keep in mind the quality of the reference depends on the quality of the file metadata.  If you drag & drop a scanned article -- one that was scanned using a photocopier -- that file will not have any metadata to create a reference.