There are three key methods to add files, e.g. PDFs, into your Mendeley desktop and web library.
Some files added to the library do not include full details. For example, the details of authors and the journal are missing from the record. You can manually add details to the fields.
1. Add Files
Mendeley app (new version)
Mendeley Desktop (old version)
2. Drag and Drop
Drag and drop files or a folder of files into the document column of your Mendeley Library. You can also drag and drop files or a folder of files, into the All references panel of your Mendeley Library app.
3. Use a Watch Folder to import PDFs automatically (old desktop version)
You may use Mendeley's Watch Folder function to import PDFs automatically. The Watch Folder function has not been implemented in the new version yet.
You can use the Web Importer to save references to your Mendeley library.
Install the Mendeley Web Importer first.
On Mendeley desktop, click the dropdown menu of Add Files, select Add Entry Manually, type details of a book or an article into the fields.
On your Mendeley library, click Add New, select Add entry manually. Enter citation details to the popup box, click Add entry to save the reference to your library.